10/20/98

SONIC TECH NOTE SERIES:

Preventative Maintenance Tech Notes 1982 to 1985 Supra MA-60 series  v4.0

Information provided is given free of charge in good faith without prejudice

Table of Contents

Section 1       5M-GE Engine
        1.0     Idling problems Page# 1
        1.1     Engine Mechanical General Page# 2
        1.2     Cam Belt Replacement Page# 2
        1.3     Cooling System Page# 3
        1.4     Valve train and Cold Startup Page# 3,4
        1.5     Exhaust System Page# 4
        1.6     Charging System Page# 4

Section 2       Drive Train
        2.0     Transmission Page# 5
        2.1     Drive Shafts Page# 5
        2.2     Differential Carriers Page# 6
        2.3     Rear axle Short Shafts & Hubs Page# 6

Section 3       Suspension
        3.0     Front Struts Page# 7
        3.1     Rear Suspension Page# 8

Section 4       Brakes
        4.0     Front Struts Page# 9
 

--------------------------------- 

Section 1 ~5M-GE Engine


    1.0: Idling problems

    On a warm day, when restarting the engine, as when leaving a gas station or coffee shop after a short visit, the 5M-GE engine may exhibit weak idling, hard starting and putting around at 500 rpm for a short period. If this happens only very occasionally it is perfectly normal and is caused by a condition called HEAT SOAK which happens after shutting off the engine.

    After shutdown the water pump and fan are no longer cooling the engine so the heat from inside the engine comes out into to engine bay cooking everything in its way, EFI sensors say "Wahoo sure is hot in here," gasoline in the fuel rail on the intake manifold is boiled {not to mention a host of other thermodynamic conditions that occur after shutdown}. All Engineering levels are taxed.

    To combat this inherit EFI {Electronic Fuel Injection} problem a number factory installed electronic and mechanical engine control systems are used, but under certain conditions they fail to correct the problem completely. For the most part EFI is a wonderful system allowing great fuel economy and silky smooth drive ability so a small bug like HEAT SOAK is still a more livable end than going back to carbs. If this rough idling symptom is happening more often than seems normal there may be a problem with one or more of the following: Cold start injector time switch, Bad Fuel, Throttle position sensor, Plugged or restricted fuel filter or gas cap, Head Gasket, Air intake leaks, Engine mechanical, EFI glycol thermo sensor, EFI air temp sensor.
 

    1.1: Engine Mechanical General

    The 5M-GE has been bulletproof reliable with many original 1982 1985 engines still out there running around the country. SONIC has several members including myself that have owned 5M-GE's that simply seem to go forever and ever, some with over 500,000.00. Km's with nothing more than belts and proper maintenance. One area that can cause some problems with the 5M-GE is related to owner neglect. The coolant system when not properly serviced can lead to engine overheating and cylinder head failure, In extreme cases I have seen 13-year-old factory coolant in some Supras.     Read section 1.3 for more info.
 

    1.2: Cam Belt Replacement

    Another area where problems may occur is related to incorrectly replaced timing belts. It is imperative that the front crank pulley bolt be properly torqued with an air impact wrench. Many club members have done back yard cam belt installs and later found that their front crank harmonic dampener pulley had come loose damaging the crankshaft keyway, harmonic dampener and cam belt drive cog. In this dilemma the only way to fix the damage properly is to have the crankshaft and other damaged parts replaced. The band aid repair is simply to weld the keyway into the crankshaft, and replace other damaged parts ugh!

    When replacing the cam belt for the second time I recommend that you replace the belt tensioner pulley, they have a life expectancy of about 190,000 km's and will commonly fail if not replaced before this distance.     When replacing timing belt be sure to use some locktite crank pulley nut.     Also, use an impact wrench with proper torque setting. If you have recently had your cam belt replaced, you should have a reputable shop check your lower crank pulley for tightness. The cam belt should be adjusted every year or 20,000 km's. This is a very simple procedure: remove five 10mm bolts holding the 5M-GE's front plastic cam belt cover, then loosen the 14mm bolt on the belt tensioner pulley the pulley will then be pulled by the tensioner spring automatically to the correct belt tension, then tighten the 14mm bolt on the tensioner pulley. You should also check your cam timing after you adjust your belt. Put the crankshaft at TDC on compression and look to see if the index marks on the cam pulleys are lined up with the index marks on timing cover back plate.     Install the plastic front timing cover and you are away.     1.3: Cooling System

    It is important to change and flush engine coolant every year; always use the best quality product you can buy. The thermostat should also be changed if there is any instability in the temperature gauge; the gauge should always run at the same position while cruising down the road.     There should be no fluctuations in the gauge reading, such as a steady climb and fall of the needle over a two-minute period. If you notice any movement you have a problem somewhere in the cooling system IE: clutch fan, dirty rad. I recommend using genuine Toyota thermostats as many of the after market brands do not work correctly for some unknown reason. I have seen some brand new thermostats that can cause the temp fluctuations right out of the Toyota box. Toyota radiator hoses seem to last forever but be sure to inspect them for cuts and cracks. Fan belts, water pump and the clutch fan should be inspected.

    I am experimenting with a new product called Polypropylene Glycol coolant which is non-corrosive and safe to the engine and the environment.     This coolant offers better heat transfer capabilities than traditional Glycol. Another advantage is that it can be run at zero pressure in the engine with minor modifications to coolant system. Call for more info.

    Your fan is used to cool your Supra on the highway as well as in slow traffic around town. Depending on engine load the fan will engage at some times to cool the engine and radiator. In the front of the clutch fan there is a coil loaded thermostatic bimetal coil that will engage the fan based on air temperature passing by the fan blade. On many older Supras after many miles the seals around the temp coil will start to seep the viscous oil from the fan clutch assay, after the loss of the oil over time the clutch fan goes on holidays and your motor gets the added benefit of about 4 hp and no fresh air intake. One of the symptoms of this problem is a floating temperature gage. See PMTN for MA-60.

    Depending on your body code there are one or more electric fans already installed on you're supra. If you want, you can wire up a simple relay logic box and switch that will allow you to fire the fans at will when the ignition key is in the on position, When you do this make sure you do not confuse any other factory systems, will the fans come on whenever needed.     This is a cool upgrade for turbo cars I have my AC fan setup to run for 3 minutes after engine shut down if desired, the MA-60's small AC fan pushes away a wondrous amount of heat from the engine compartment.

    Another super upgrade for MA-60 is to replace the 5M-GE clutch and fan with the 7M-GTE unit. Some trimming of the fan shroud is needed but your supra will run as cool as a cucumber. The 7M GTE fan and clutch move a sizeable amount of extra air through the radiator.
 

    1.4: Valve train and Cold Startup

    With most 5M-GE engines it is normal to see some chalking of the edges of the cam lobes. If you are changing your valve cover gaskets and notice this roughness on your cams lobes do not panic. I can recall the first time I noticed this on my 5M-GE when it had only 50,000 km's on it. I went running to my dealership saying that my engine was defective. At that time my dealership told me not to worry about it and that they would replace the cams if they became a problem. Several years later after looking at the cams in other Supras belonging to other club members who had their cams replaced by Toyota due to the marks, I realized that Toyota was not telling stories, the new cams looked exactly like mine and my 5M GE now had 95,000kms on it. That was many years ago, today my original 5M-GE engine has 322,000.00 Km's with out being touched, the cams still look the same way. I decided to replace my original 5M-GE in May 1993 with a super hot HKS tweaked 7M-GTE from a crunched 1989 MA-71 Supra Turbo. Call for more info on the Supra GTE conversion kit.

    When you are starting your 5M-GE for the first time of the day, many 5Ms will make a loud clack-clacking valve lash adjuster noise. The work around for this problem is simple, shut the engine off immediately after starting, then restart the engine, it will usually run quietly after you do this, if not repeat the stop and start. With practice you will find you can actually just turn the engine over without starting it to achieve the same result. The 5M-GE engine does this because of an air lock condition that occurs in the oil pressure regulator bolted to your cylinder head between the cam boxes. This work around makes your starter work harder but the result of less wear and tear on your valve train is worth it.

    I have seen proof that oil leaks at the exhaust cam box are caused by heat generated by the exhaust manifold. On a number of cars that had cam box oil leaks, the leaks went away completely with the installation of an exhaust header.

    Turbo magazine and other club members have witnessed the documented durability of my 5M-GE. After the many km's it is still a strong engine, it ran most of its whole life with the TRD exhaust header and HKS exhaust system. I am sorry to say it is now resting on a wood pallet in my shop, waiting for the day it will again propel an MA-60 down the highway.
 

    1.5: Exhaust System

    The only maintenance area relating to the exhaust system is with the exhaust manifold on all 5M-GE engines. You should also have a close look around the motor for cracked, loose or damaged air intake plumbing and vacuum lines. Also re-torque all of the 14mm nuts on the manifold to head and also exhaust header pipe to exhaust manifold. An exhaust header and good exhaust system are the best upgrades for the MA-60. The exhaust system will improve fuel economy and performance. The engine will run cooler and have a beautiful exhaust note similar to the purr of a Jaguar, or Lotus. HKS make a great 60mm system for the MA-60, I think it is soon to be discontinued so act fast there are only a few left in the world. My HKS exhaust lasted for over ten years, it is now on a club members car along with the super high quality TRD exhaust header.
 

    1.6: Charging System

    Many service shops are replacing the original Denso Toyota Supra alternators with converted GM Delco units. Do not let this happen to your Supra. The original Denso Toyota alternator is a much better quality alternator than the GM unit the shop is trying to sell you. Furthermore the GM unit will not charge the battery when the engine is idling, and can self-destruct if you run your 5M-GE to its 6,500-RPM red line frequently.

    Your original alternator is very easy to rebuild and will usually only need new brushes. If your Supras emergency brake light and charge warning light came on together when your alternator failed, your alternator will need a voltage regulator as well as new brushes. The slip rings on the Denso rotor are seldom worn because they are made of stainless steel.

    With the MA-60 series cars there is a common condition with the charging system. It is actually a handy indicator of the problem. If your MA-60 supra alerts you with a charge warning light and brake warning light at the same time the problem is in your voltage regulator, located inside the alternator.
 

    Section 2 ~Drive Train     2.0: Transmission

    For more than a decade the only transmission complaints reported by owners are related to how can my Toyota Supra transmission shift faster and slicker than it does already. Supras have always had very smooth, strong & slick gearboxes, the 1982 to 1992 {W58} in the MA-67 and MA-70 non-turbo as well as the super beefy {R154} from the MA-71 turbo car have all proven bulletproof to the end! Therefore the only suggestion I can give you is toward advice on lubrication. Winter cold climates use Dextron 11 if bearing noise or hard shifting is experienced when cold, do not be alarmed by a small amount of input shaft bearing noise, this is normal with some Toyota transmissions. Also a ticking or slight squeaking sound can normally come from the clutch release bearing. Summertime use Red Line or Amsoil synthetic gear oil. These oils work wonders in Toyota boxes, reducing friction and making the gears shift very easily. I run a W58 transmission in my 82 Supra with a 7M-GTE and have experienced fantastic reliability at over 425 HP. 
 

    The automatic Transmission used in the MA-60 series Supras has also proven to be bulletproof. Be sure to change the oil regularly. Dirt and oil break down are your transmissions only enemy. You change the oil by draining the transmission pan, please note: you can only change 2 liters of the oil at a time; most of the oil is retained in the transmission and converter and will not drain out. Change the oil regularly when you have your engine oil changed, this way you will eventually replenish all the old oil with new.
 

    2.1: Drive Shafts

    Supra drive train components have always been very robust, however some service shops always seem to be able to find a way to damage the odd one.     Relating to Drive Shafts be very careful when you are told by a service shop that you need to have your Supras U Joints replaced. In 12 years with this club I have never seen a drive shaft that was so worn out that the joints were loose. If you have a vibration or a noise please do not assume that your drive shaft is worn out. If you let just anybody try to install U Joints in any Supra 1982 to 1992 drive shaft you will most definitely get your car back with the original noise you were concerned with fixing plus a few new ones to boot. 

    Note: Supra drive shafts almost never fail on their own they need help from: car accidents, rust, inexperienced service shops.
 

    2.2: Differential Carriers

    The only real problems with the differential in the MA-60 series is relating to the fact the LSD {limited slip differential} clutch pack does not have a great deal of tension. This means that the differential is loose and does not have much limited slip action. Toyota went to great lengths to improve the LSD in the MA-70 series and in hindsight made them too tight. Sure is hard to satisfy everybody.

    Another condition that may trouble your Supras differential is lack of regular oil changes; this will lead to differential failure or premature wear out. The MA-60 differential holds a very small amount of oil {1.2 liters} so it needs to be changed regularly. Cold climates are very hard on the differential. I recommend using a good quality synthetic in cold climates. I do not recommend standard 80/90 wt oils in any Toyota differentials. Using a 75/90-wt LSD differential carrier oil from Ford motor company makes Supra differentials run quieter and smoother than any other oils tested. This oil has increased protection for the clutch pack and has proven to be the best differential oil for all Supras from 1982 to 1992. Don't ask me why, all I can say is this oil works like magic.

    Note: A number of club members are using synthetic oils from Amsoil and Esso in their differentials with good results, one word of caution should be noted."Synthetic oils may make a some differentials that are already noisy, noisier."
 

    2.3: Rear Axle Short Shafts & Hubs

    Unlike the front wheels hub and spindle setup the rear wheels are spun on a two piece splined short shaft assembly that is installed into the rear control arms on tapered bearings with a crush sleeve preload setup, the same way a pinion shaft is installed into a differential. Because of this crush sleeve arrangement it is impossible to just quickly disassemble the short shafts for service and greasing. Because of the unserviceable of this area, it never gets serviced, and as it turns out it the short shafts have never been any problems what so ever. The only way you can hurt them is with curbs and accidents. I am telling you all about this because I used to spend some time wondering how long this setup will last. My conclusion is: my Supra now has 325 HP and 330,000 km's on the factory shafts and still no problems other than some tolerance in the short shaft spines. "If it ain't broke don't fix it."
 

    Section 3 ~Suspension
    3.0: Front Struts

    Many years ago when the 1982 and 1983 MA-60's were almost new dealerships around the country were receiving complaints from Supra owners relating to wheel vibrations and shimmies felt in the steering wheel.

    Depending on which dealer you were talking to the story was different, some were saying the suspension had a design flaw while others were blaming the Dunlop D series tires. After my dealer had completed their fifth try at re-balancing my Supras wheels, I decided that the problem was not related to the wheels or tires.

    By taking a fresh approach to solving the problem I discovered a couple of things that could be causing the vibes. The first area was relating to the front suspensions tension compression rods bushings, the bushings were very soft and allowed the front wheels considerably soft pinning. By fabricating some steel inserts I was able to tighten the bushings considerably. This was a worth while upgrade; my car handled superbly and had considerably reduced steering wheel vibes. When disassembling the tension compression rods I was amazed at how worn my factory stock front struts looked; some leaking as well as worn shock shafts. I decided to replace the stock oil based front struts with an after market KYB GR-2 gas front strut. Presto-solveo! My Supras wheel vibes were nowhere to be found.

    I passed this information on to a number of the local Toyota dealerships as well as to Toyota Canada. Shortly later in the second quarter 1984 Supras were shipping with upgraded tension compression rod bushings kit part #48674-19105 as well as upgraded gas charged front struts.

    Years later I learned through the grape vine that the original test mules that went to lotus had much stiffer T.C. rod bushings but they did not make production. The moral of this story is; if your Supra has front wheel vibes felt through your steering wheel if may not be your wheel balance.
 

    3.1: Rear Suspension

    The rear suspension on the MA-60 has proven to be very robust and simple to set up. The only adjustments are for toe in. camber is not adjustable and this leads me into an area that needs to be mentioned. If your rear suspension feels low or you notice wheel hop when you spin the tires on slippery road surfaces you should upgrade your rear shocks. Club members have tested may types of rear shocks and the best ones are of the Gas types made by KYB or Tokico. This is the only upgrade that you should do to your rear suspension. I have tried and have also seen a number of club members using after market springs of all different types {TRD, EIBACH, SUSPENSION TECHNIQUES} etc in the MA-60 series Supras, this is the best way I know of to screw up a MA-60's handling and performance. Been there done that. After upgrading my 1982 MA-67 to the 1989 7M-GTE engine I tried a number of things to try to get the car to hook up in a straight line and around corners.

     See Turbo & High Tech letter text insert     "Some of the changes I made to get the car hooked up were to replace all the shocks and struts, they seemed as if they were in fine shape with the 160 hp 5M-GE, but with the new potent turbo engine the supra was a handful to say the least. I used locally available KYB's that I have had great success with in the past. I also found that the rear suspension ride height was critical to optimum performance! It should be as close to factory spec as possible, I use the stock GTS front & rear springs. Short springs cause the rear suspension to have way too much negative camber under acceleration making the car loose bite and snake of sideways. The stock rear springs and KYB shocks helped reduce the wheel spin as well as settled down the tendency to over steer in a straight line. I also installed a new set of tires, BFG Comp T/A's, 245-50-16's in rear and 225-50-16ís up front replacing the very old first generation Goodyear Gatorback 225 50-16's at all four corners. This reduced the wheel spin considerably, and allowed me get on the car harder in first gear than was previously possible with the old setup. As well the slightly taller rear tire's now make overall gearing factory stock, 2450 RPM at 100 KPH. I can't seem to get total control of wheel spin in first gear on all road surfaces.     Sometimes second gear can cause wheel spin and over steering problems if the attitude of the car is anything other than perfectly straight. It comes in right after the Turbo spools.  Proverb; Plentyohorspower     "IT IS DIFFICULT TO MAKE ANY 3100 LB VEHICLE WITH 300 + HP NOT SPIN THE WHEELS."

    Some of you may remember that the MA-60 suspension was set up by an English car company called LOTUS. Toyota owned a good-sized chunk of Lotus during the time of MA-60 development. Lotus set the overall factory spring rate to work well on the street under many different road conditions. If you are setting up an MA-60 for auto-crossing or slalom you then may want to look into the TRD or Eibach spring setups. The excessive negative rear camber that rips the inside off your rear tires on the street is an advantage going around a racetrack. If your Supra has more than 300 hp under the hood the stock springs will be your best choice for 1/4-mile times.
 

    Section 4 ~brakes 4.0: Brakes

    Brakes on all years of MA-60 series cars are very good. The only problem with them is relating to the fact that the pad material is so hard the brakes seem to last forever. It is not uncommon to see MA-60s with over 200,000 Km's on the original front and rear pads and rotors. Due to the use of this hard material in the pads some cars will develop rotor fade causing high rotors temperatures, causing the rotors to go out of round.      On two occasions I have removed the front rotors from my Supra to have them cut down, I then put them back on the car with out changing the pads.

    On cars driven in salty conditions it is normal to see the rotors corroding very badly causing the cooling fins to become ineffective. After market rotors are cheaper but will wear down if you use the stock pads. If you use after market rotors use after market pads as well. Many years ago a smart guy told me "never handle new brake pads or rotor surfaces with your bare hands because the oil on your skin will cause glazing of the pad material. I have had many people crying with tears over this but to this day I have still not proven this statement wrong or right. I still use it today because it makes a certain amount logical sense, why do I have to touch the surface to install the parts? I don't.

Currently I am researching high performance after market brakes for my Supra. I need to make my car stop better than the stock brakes are capable of. My Supra is a dangerously fast car.

    Another important tip for all MA-60 cars is to be sure not to over tighten the wheel lugs. The factory torque spec is 55 foot/pounds, always torque to this value. I have seen Supras where the wheels lugs were torqued to very high values 140 foot/pounds, this can cause rotor distortion resulting in brake peddle pulsation. I always torque the wheel nuts with a torque wrench.

    Always check all your brake lines, it is very rare to find cracked lines but on cars driven in cold climates sometimes have fine cracks. Another good preventive Maintenance tip is to flush your brake and clutch master cylinders reservoir out with new fluid every two years, always use good quality fluid and be careful not to spill any brake fluid on your Supras paint because it will damage the paint on your car.

    Regards

    Reg Riemer

    End of File! 

    SONiC 
 
 
 


Supra Owners Network In Canada FROM THE HOME OF THE SUPRA GTE 
Information provided is given free of charge in good faith without prejudice
Visit my Supra Page at http://suprasonic.org
Calgary Alberta Canada. 
Office#1-403-259-3106 

Back to SONiC Home Page

Back to SonicTech page