Burb modified and im confussed..

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beachsuburban

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Hello, I have a 1989 v2500 suburban, and the transmission decided it was finished... It wasn't going into 2nd, I did the governor , tv cable with no help, dropped the pan and teared up a little inside, black thick fluid in the pan.
So my search began and I found out about all the different 700r4's out there. Not trying to spend the $1400 I was quoted for a rebuild, I want to explore my options.
The burb came with several mod's 4" lift, 35" tires, headers to custom exhaust, so I know it has had alot of hands on it over the years. What Im working with now, and what I could do is where Im a little lost.

So the ID stamp I have on the trans is:
2KJM156B
A lookup tells me it's a 1992, so does anyone have advise for me as to what I should do... Get it rebuilt, or find another one out there used, or already rebuilt, and since they are a little hard to find possible switching to another model. Also if it's advised to just replace what I have, what are the types to look for so I wouldn't have to modify what I have.When I search for used ones there are alot of 2wd ones, are they an option as well. It also has the np208 t-case.
Thanks in advance to such a great community!!
 
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74 Shortbed

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Have the one you have rebuilt it's a good one if it's a 92, if you pick up a used one you won't know what kind of shape it's in and it'll probably need rebuilding anyhow, or at least modified to the way you want it, rebuild yours the way you want it and you'll know what you have..
 

yevgenievich

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2500 should have a th400, but some one probably put in a half ton transmission in (700r4) for overdrive. A better setup would be th400 or 4l80e(both will need new input shaft in the t case and 4l80e needs a computer). Or get a good quality rebuild of the 700r4 with upgrades to serve better under stress.
 

shiftpro

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Those 35" tires finished off the 700.
With overdrive transmissions you need to gear down considerably. When a 700 is over geared (too high a ratio) it hunts back and forth for 4th gear, creating excessive heat. Also, if the torque converter can't lock up, also a symptom of final drive gearing being to high, it's going into meltdown.
 

shiftpro

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Hello, I have a 1989 v2500 suburban, and the transmission decided it was finished... It wasn't going into 2nd, I did the governor , tv cable with no help, dropped the pan and teared up a little inside, black thick fluid in the pan.
So my search began and I found out about all the different 700r4's out there. Not trying to spend the $1400 I was quoted for a rebuild, I want to explore my options.
The burb came with several mod's 4" lift, 35" tires, headers to custom exhaust, so I know it has had alot of hands on it over the years. What Im working with now, and what I could do is where Im a little lost.

So the ID stamp I have on the trans is:
2KJM156B
A lookup tells me it's a 1992, so does anyone have advise for me as to what I should do... Get it rebuilt, or find another one out there used, or already rebuilt, and since they are a little hard to find possible switching to another model. Also if it's advised to just replace what I have, what are the types to look for so I wouldn't have to modify what I have.When I search for used ones there are alot of 2wd ones, are they an option as well. It also has the np208 t-case.
Thanks in advance to such a great community!!

Beach what do you want to do with this truck?
 

beachsuburban

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Very interesting so far... So there are 3 wires coming out of the trans, only the green one is connected, now wondering what they did that for? We take it on the beach all summer, so alot of sand. Most all trucks take air out to drive, I leave mine set around 32psi and was always good on and off road.. Where we live the speed limit is 25-45, also go about 7 miles each way... so I might be able to get away without OD? Thanks for all the input!!
 
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shiftpro

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Do you know what the gear ratio is? I mean the final drive in the differentials...
I doubt it is 488, which is about what you need with 35s and your 700r4.

If you got your truck even slightly twisted, which sound unlikely in your application, tires will contact fenders.
I would seriously consider small tires, like 32s. I'm just thinking about your eventual rebuilt 700.

If you changed the transmission, say to TH400, you would need a different adapter (between transmission and transfer case) as well
as modding your rear drive shaft. It would need to be shortened. Also the front driveshaft may very well also need to be extended.

Sorry we're getting into a can of worms here...
 

beachsuburban

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So not to sure, but I looked and saw a tag on the front It has 45-11 4.09 rear has markings of cfd 9690 and gm2 ,and has 14 bolts.The fenders were pushed in assuming for the tire clearance. Changing over sounds exactly like a can of worms I don't really want to smell. So I might keep that closed unless convinced otherwise... It has dry rotted tires, so going down on the next tire purchase is a option. But not sure how it would look?
Do you know about only the one wire (green) being hooked up? Just wondering if your mention before is still possible if the OD is disconnected.
 

yevgenievich

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Lock up might still be connected internally to lock up in 4th if there is only one wire running to it. A good rebuild should be ok.
 

beachsuburban

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Thanks for the advice everyone:)
 

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