My 1992 chevy 1 ton with the 6.5l diesel trubo auto trans wont shift in to high gear

Asked by Jan 26, 2014 at 08:20 PM

Question type: Maintenance & Repair

15 Answers


Well it's a '92 so you have the 4L80e. Those are tough transmissions. The main reason that you loose 4th (OD) is the band slipping. I'm very familiar with the 700r4 and 4L60e. Hope someone else can shed some light on it. Is it in a 2wd or 4wd.

Best Answer Mark helpful

Its a 2 and is it fixable

Well this is y i lost high gear my son knocked it into rev wen we was going down the road i was thanking it was the valve body

Wat other trans will work in my truck


Depends on the wear on the band (how much lining is left). If looking to see if it can be adjusted. Well at least the 2wd ones are a dime a dozen for a good used unit. 4x4 is a little harder to find. A 4x4 700r4 and 4L60e's are getting really hard to find. I was going to start running 2wd 4L80e's with divorced transfer cases in stead of looking for the smaller units. Hence my intrest on the topic. I have a manual for the 700 and 60 but not the 80 yet. We will se what's online.


Sorry was typing while you were typing. Reverse Eh. Dam. Did it make a noise???


Ya a granding i snached it back down into od and i lost od but everything else works fine

Wat other trans will work in my truck i need it fixed im losing money wen its down


Reverse still works!! Ok know that I know what happened it sounds like maybe a sprag broke and won't spin the planetaries for OD? It may last for awhile as a 3spd or die. You never know with a tranny but I doubt it's that band. Any 1 ton from 1991 to 2000 (new body style) will have the 4l80e. From what I know they are all the same. They are also in the 3/4 tons and some 454SS's but I cannot confirm the output splines (should be the same as yours). But the cheaper ones are in the panel vans. They should all have this tranny. The older trucks have the 400 which you could use but you would need to hook up the kick down and I'm sure you'll find a 80 faster and cheaper than a 400 (everyone wants those).


Both gas or diesel trannies would work. Your shifting is controlled buy the TCM (tranny control module) in your engine bay. It will just plug into the new one.

Ok so u thank its just the spung is it hard to replace


Sprag. They are small mechanical clutches. They are used to allow rotation of a shaft in one direction but not the other. The reason that I suggested it is that I had one go in a 700r4 and we lost OD. Eventually all the forward gears quit?? No they are not easiy to replace. The pump, input shaft, most of the clutch packs have to be pulled to get to the SOB and that is the state if my first 700r4 as we speak, I got mad and bought a used one. Unless someone helps get you going it is a pain untill you learn the tricks. I'll rebuild a motor but I wont touch those SOB's. I recommend replacing. New or used. Rebuilding would leave you with out it for awhile. A shop could do it quickley but they cost an arm and a leg.

Ok so would a 700r4 r a 400 work on my truck


Yes but a 6.5 would destroy any 700r4 that costs less than 2000. The 700r4 requires a T/V cable hook-up and from a guy that has 6 out of 8 that are blown up right now, don't use this tranny. The 400 would work but unless you know where one is the 80 will be cheaper. The 400 is a 3spd and it's top gear is the same as your 3rd right now!!!! The 400 would require a kick down cable. You may need to modify the driveshaft depending on what it cam out of?

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