Transmission Fluid Poll

What kind of transmission fluid do you suggest?

  • Royal Purple 75w90

    Votes: 0 0.0%
  • Redline 75w90NS

    Votes: 0 0.0%
  • Straight Synchromesh

    Votes: 0 0.0%
  • Other

    Votes: 0 0.0%

  • Total voters
    0
  • Poll closed .

kulangflow

New member
I recently purchased my first AllTrac, and I am currently in the process of redoing all the fluids. I have done a great deal of research on manual transmission fluids for this car, as there is a great deal of information on it here, and I have boiled it down to a few options.

It should be known that my car has really bad synchros, so I will be replacing the transmission in the next year or two.

So, what do guys suggest?

-Royal Purple MaxGear 75w90. (In stock at Autozone for $17/qt)
-Redline 75w90NS. (Can only find online for $10/qt + shipping)
-Straight Synchromesh (In stock at Autozone for $7/qt)
-Other

BTW, it's a 1988 IMSA GTO edition with 142,000 miles. Also, I live in Utah so it can get down to below freezing temperatures.

Thank you!

-Brian
 

Dracov

Member
Switching to Redline made my synchro issues a little bit worse than with whatever the old fluid was. Still on the 165's original gearbox
 

kulangflow

New member
Dracov":11zx9c6z said:
Switching to Redline made my synchro issues a little bit worse than with whatever the old fluid was. Still on the 165's original gearbox

Were you using 75w90NS or just 75w90? What I gather is that the NS version is needed for the synchros in our trannies.
 

grip addict

New member
used valvoline durablend 75-90 for a while, and the car shifted really well. i know a couple of other people on board are using it too.

mmm... the smell of gear oil.
 

toayoztan

Moderator
grip addict":3l2hq0m0 said:
used valvoline durablend 75-90 for a while, and the car shifted really well. i know a couple of other people on board are using it too.

mmm... the smell of gear oil.

That's what I use to, no issues at all.

Bryan
 

kulangflow

New member
grip addict":1cze3o5r said:
used valvoline durablend 75-90 for a while, and the car shifted really well. i know a couple of other people on board are using it too.

mmm... the smell of gear oil.

How would Valvoline Durablend compare to the Valvoline SynPower? My local Checkers has the SynPower in stock for $10/qt, but no Durablend to speak of.

Thanks again for the assistance!

There is a ton of info on MTF fluid, but most of it is from 2-3 years ago. It makes me wonder what people are using now, if changed at all.
 

Corey

Active member
I've tried both Redline and Royal purple.

redline went into the old E150F tranny - I don't think i really noticed any difference in shifting when compared to the fluid originally in there. Still had the usual 2nd gear hi-rpm grind.


Royal purple went into my newer E154F tranny with the better syncros - so i can't really compare the two.

I'm happy with either one, they are both good oils.
 

RafaCalde

New member
i was thinking of using royal purple, 2 qts of maxgear and 3 qts of synchromax. anyone think this would be bad? should i just use 5 of synchromax or 5 of maxgear?
 

Simba

New member
I've used virtually everything. Mine likes Redline MTL the best. Slightly thinner than the usual 75/90's.

I've also found that Redline Heavy Shockproof is simply awesome in the diff.
 

tissimo

New member
Simba":2m1tosmh said:
I've used virtually everything. Mine likes Redline MTL the best. Slightly thinner than the usual 75/90's.

I've also found that Redline Heavy Shockproof is simply awesome in the diff.

I ran shockproof in my old mkiii supra trans and loved it. They have a first gear thrust washer issue when you're making big power/torque and wanted to be safe, but it shifted smooth and didn't have any issues.

I'll probably run MTL in my 90 after I do the clutch. It ran good in my supra before.
 

RedCelicaTRD

Moderator
My st185 has Mopar 80w90 in trans and rear diff. Mt st165 has Valvoline full synthetic in the trans and Mopar 80w90 in the rear diff. St165 grinds because the clutch is not adjusted properly. St185 is hard to shift due to short shifter. Other then that I'm happy.
 

wizzards581

New member
i used pennzoil GM synchromesh for 3yrs ~15k miles... nothing wrong... i might change it in summer... :smokes:

i notice nowdays Honda owners are starting to use these stuff because it hides the grinds... :wink: at least for me...
 

kulangflow

New member
I found Valvoline Durablend in stock at Autozone for $6.49/qt, so I went ahead and picked it up. I'll do the drain/refill over the weekend and hope for the best. I'll report back at how well it does with my synchro-challenged tranny.

Thanks for all the replies!
 

kulangflow

New member
I did the change-over last night to Valvoline Durablend 80w90.

Wow, it was really annoying to pump in the new fluid. After the third quart, I filled a small bucket with really hot water and placed the last two bottles in it. This thinned it out and helped a lot.

Anyway, I could tell the difference right away with the shifting. It still doesn't shift nearly as well as my '86 GT-S did, but it's a ton better than it was. Second gear is the only problem gear left. The rest are nice and smooth now.

If I get bored one of these days, I might drain a quart of it and replace with a quart of Synchromesh to see if that helps a bit more. I'm decently happy with it right now though.

Thanks again for all your suggestions!

-Brian
 

Jason88AllTrac

New member
Other: I also run a mix... mostly Redline MTL, but a quart of Mobil1 (GL5) which has the EP/hypoid additives for the center diff. It shifts WAY better than with regular valvoline GL5 I threw in after doing the clutch. I have had very good luck on other cars with redlines MTL, shockproof, and royal purple.

kulangflow":n5tzkcli said:
I did the change-over last night to Valvoline Durablend 80w90.

Wow, it was really annoying to pump in the new fluid. After the third quart, I filled a small bucket with really hot water and placed the last two bottles in it. This thinned it out and helped a lot.

LOL... pumping it in is the tool way to do it. I just run a hose down to the fill from above, pouring it into a funnel is sure hella-easier than trying to wiggle a little pump back an forth for half an hour.
 

kulangflow

New member
Jason88AllTrac":8lb6f2kw said:
LOL... pumping it in is the tool way to do it. I just run a hose down to the fill from above, pouring it into a funnel is sure hella-easier than trying to wiggle a little pump back an forth for half an hour.

Yeah, apparently. The pump was lame. The reason I used it is because somewhere on here the pump was recommended over the gravity drop. I'll definitely be using the gravity drop next time.
 
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