Trans 1985 4.2 Laredo CJ7 T5 Manual Transmission Oil

[hoods5]

Hey guys,

Ok so I've read many threads but nothing really current. I have a, 85 CJ7 AMC 258 i6 / 4.2l with the T-5 manual Transmission .

What oil do I use? It looks like it should be the synchromesh but what weight 75W90????

Any recommendations that you can give me would be much appreciated. Thanks.

Dave

 

[CJ]

You can read the debates on this until your eyes bleed.
What I know and have used. GL4 is specific for a syncro Transmission but a low sulfate GL5 such as Valvoline will work. You and I are in FL so cold weather is probably not a big issue so synthetic is not a must have. 75w90 GL4 is fine for FL. 75w90 in cold weather can make it slightly more difficult to shift. Do not use any ATF.

 

[hole]

I ditched the T-5 years ago, but I was running 75/90 GL4/5 and it would grind the 3/4 shift. Synchromesh eliminated that until I pulled it in favor of a T19.

 

[hoods5]

So does synchromesh have a stated weight to it or is it all the same weight? Is it al 75W 90 or are there different weights? I don't see any weights listed on any of the synchromesh bottles that I've seen online.

 

[CJ]

So does synchromesh have a stated weight to it or is it all the same weight? Is it al 75W 90 or are there different weights? I don't see any weights listed on any of the synchromesh bottles that I've seen online.

A syncromesh is the brass toothed ring between the gears in the Transmission that are designed to equalize the speed of the gears while shifting so they do not grind. It is not in the oil. It's the additives in the oil that make it specific for synchronized transmissions, GL4. 75w90 is the viscosity of the oil. 75w when cool and 90w when at temp.
The syncromesh bottles are an addictives for standard 75w90 oil so it turns into the oil type you require when mixed.
Long story, short, just buy 75w90 GL4 oil.

 

[hole]

So does synchromesh have a stated weight to it or is it all the same weight? Is it al 75W 90 or are there different weights? I don't see any weights listed on any of the synchromesh bottles that I've seen online.

I'm not sure of the additive CJ is speaking of, but the product I used was intended to be used straight out the the bottle. I dont remember what brand (Valvaline, Penzoil,etc ) nor do I remember if it came in different weights. Just look for Synchromesh for manual transmissions, I dont think brand will matter.

 

[hoods5]

Perfect thanks all.

 

[Flyn'Hawaiian]

Hey guys,

Ok so I've read many threads but nothing really current. I have a, 85 CJ7 AMC 258 i6 / 4.2l with the T-5 manual Transmission .

What oil do I use? It looks like it should be the synchromesh but what weight 75W90????

Any recommendations that you can give me would be much appreciated. Thanks.

Dave

w does not mean weight. w means winter

 

[CJ]

I'm not sure of the additive CJ is speaking of, but the product I used was intended to be used straight out the the bottle. I dont remember what brand (Valvaline, Penzoil,etc ) nor do I remember if it came in different weights. Just look for Synchromesh for manual transmissions, I dont think brand will matter.

Same thing you are, just do not add it if the oil is already GL4/5 rated.

 

[hoods5]

I’m going to completely drain all of the oil so that won’t be an issue.

 

[Arlee]

Reviving this old thread on proper T-5 fluid. 1984 T-5 , manual calls for Part # in 1984, 89 83 000 000. Have seen all sorts of recommendations from Dexton II ATF, to 75W90 GL4, straight 30weight, synchromesh 5W-20 and so on...WAY different oils. From what I gather, AMC kept changing recommendations due to heat, noise and poor lube issues. So the age-old recurring question...WHAT IS THE CURRENT RECOMMENDED FLUID? I just acquired this CJ7 (one owner!) and am getting her all fixed up and all fluids changed (after leaks located and fixed).

 

[TSB8C]

Factory Part # in 1984 was 89 83 000 000
Superseded by part # 4549636
Superseded by part # 4874464
The T-5 fluid must meet specification SM 9224
Shell owns Pennzoil
Pennzoil supplies Mopar
Mopar part # 4874464 which is Pennzoil 3501 = synthetic 5w-20
Amsoil synthetic manual synchromesh transmission fluid 5W-20 meets SM 9224.
Prior to 1991 5w30 or 30w is acceptable fluids for the T-5, depending on climate.

Again, factory recommends lube that meets specification SM 9224 for the T-5 transmission, (GL4 5W-20). Prior to 1991 5w30 or 30w is acceptable fluids, depending on climate.

 

[Arlee]

I checked the Penzoil syncromesh 3501 and it states it is GL3, thought we had to have GL4 in these transmissions? Reading the valvoline syncromesh is preferable, but that appears to be a thicker gear oil like 75w90?