transmission fluid for 71 Jeepster Commando

[AZbman]

I have the original three speed "Turbo HydraMatic" automatic transmission in this rig, and it was rebuilt within the past two years. Since that time, I have noticed quite a bit of transmission fluid leakage, which I need to address. In the meantime, I continue to add transmission fluid. The question being - what type of fluid should I purchase that is closest to what is specified in the service manual.
Service Manual states: GL-4 GM Type A Armour Institute Qual. AQ-ATF SAE-90 (summer) or SAE-80 (winter)
NOTE: based upon reading the manual, I purchased and recently added Redline MT-90. Prior to that my records show that I added ATF+4. Which means I have both in the transmission oil pan. Should I drain all fluid from the transmission, and replace with the same? If so, what should I purchase?

 

[Hirev]

It sure seems your manual is out to lunch. Turbo HydraMatic is a GM automatic transmission you should be using dexron not gear oil. Old jeeps used either GM or chrysler automatic transmissions. GL-4 is used in old GM manual transmission among other things. GL4 also was not around in 71.

 

[slacktide_bitog]

Any Dexron type ATF should be good for your (GM) Turbo Hydramatic.

Type A is what GM used before Dexron, but Dexron is backwards-compatible with the old Type A.

 

[ripcord]

You want automatic transmission fluid labeled Dex/Merc or "suitable for use where Dexron IIIh is called for."

 

[Chris142]

Dexron / mercon fluid . Back then they only had Dexron or type F and the F was used only in Fords

 

[AZbman]

thanks all, so it sounds like I should drain out the GL-4 / Dexron mix and replace it with Dexron / Merc fluid.

 

[ripcord]

Yeah, most definitely. Gear oil in an automatic isn't going to end well.

 

[michaelluscher]

You can still get Dex-IIIH fluids, if you feel like seeking them out

If you're feeling fancy, some people feel that the later (synthetic) improvements in TES-295 fluid make it the best option for Dex-III applications

Or some store brand Dex/Merc fluid would also be fine, anything as long as it isn't gear oil mixed in with the ATF

 

[Chris142]

I see where you got confused. The standard 3 speed is a manual transmission. Most likely a 3 on the tree.

The automatic is just below it and called for type A fluid which was superceded by dex2 then dex3. I definitely would not run the thing with the gear oil in the pan as that is the complete wrong stuff for an automatic transmission .

 

[Chris142]

This is what you want. It's bright red as to not be confused with other fluids.

The ATF+4 is also incorrect

 

[ripcord]

One more piece of info, if you have run the rig, you've mixed the gear oil in with the rest of the fluid and a simple pan drop and refill won't get all the gear oil out. You're either going to have to do multiple drain and fills or do a cooling line flush. Here's a video showing one way to do it.

 

[clinebarger]

You're reading it wrong!!

Transmission, Standard.........GL-4 SAE90 SAE80

Automatic......GM Type A ATF (Use Dexron III or Dex/Merc)

You likely have a TH400.