What Trans do I have? 700R4 or TH400?

[Gyoas759]

Hey all. Brand new to the site but I love what I see. I just bought a 1989 3/4 ton suburban 4x4. I am just getting started into doing some tune up/rust repair/paint and all and I'm getting mixed reviews on which trans I've got. The truck has the 5.7liter V8 in it. Any way to tell which trans I've got?

 

[k5warwagon]

three speed auto is th400 and 4spd auto is 700r4

 

['86erfixer]

i believe they came stock with the 700r4's. but by the time we get em, who knows whats under them. best bet is to post some pics (get your post count up) & let someone with more knowledge than i help you out. crazy geniuses around here

 

[76zimmer]

check here:

http://www.technicalvideos.com/identify_my_transmission.phtml

 

[dieselponyexpress]

Option was a TH400 in these years. Should be a TH700/NP241 combo though, this was standard. If your shift indicator looks like "P R N D 2 1" it is the TH400. All others do indicate a TH700. Look at the described links or check your option codes inside the glovebox to make sure.

Walter

 

[Kjunky5]

If your shift indicator looks like "P R N D 1 2 3" it is the TH400.

Walter

I think you mean P R N D 3 2 1 (or P R N OD D 2 1), and then it would be a 700r4. Not a 400.

 

[dieselponyexpress]

I think you mean P R N D 3 2 1 (or P R N OD D 2 1), and then it would be a 700r4. Not a 400.

Correct man, sorry for the mismatch . Fixed it and hoping nobody got hurt. Probably dreaming for years of a really HEAVY DUTY 700 made my brain a little weak . . .

Walter

 

[Kjunky5]

Correct man, sorry for the mismatch . Fixed it and hoping nobody got hurt. Probably dreaming for years of a really HEAVY DUTY 700 made my brain a little weak . . .

Walter

There are heavy duty 700r4's. They're called 4L80E's

 

[4xcrazy]

There are heavy duty 700r4's. They're called 4L80E's

not in an '89.

 

[Gyoas759]

Thanks guys. looks like it's the 700R4. Next question, I crawled underneath to give the trans a closer look and came across a little round plate about an inch and a half in diameter stamped onto the back of the transfer case. It reads "new process gear" has some model numbers stamped into the plate. (Can't make them out in the dim light.)

Any thoughts on what that might indicate? I'd post a pic but I'm not up to my 15 post count yet.

 

[Kjunky5]

not in an '89.

No duh. Notice the wink.

 

[Kjunky5]

Thanks guys. looks like it's the 700R4. Next question, I crawled underneath to give the trans a closer look and came across a little round plate about an inch and a half in diameter stamped onto the back of the transfer case. It reads "new process gear" has some model numbers stamped into the plate. (Can't make them out in the dim light.)

Any thoughts on what that might indicate? I'd post a pic but I'm not up to my 15 post count yet.

It's the model of the transfer case. Should be a NP241 (2.72:1 low range).

 

[rusty79gmc]

Wow, thats great info, although i cant believe you can actually see the number tag on your transfer case. lol. mine is covered in 36 years of grease, dirt, mud and grime. i was able to scrape some of it off with a chisel and found my two pto connections. now i just need a good winch (don't we all?)

 

[4xcrazy]

No duh. Notice the wink.

yeah, nice recovery attempt there

 

[Kjunky5]

yeah, nice recovery attempt there

That just doesn't make any sense bro. Recovery from what?