I have an 82 Blazer with the 6.2 and i feel like im having transmission slippage and maybe a bad torque converter... being new to this engine and what not i nvr really realized it... but the way everyone talks the 6.2 either has the turbo 400 or the 700r4... mine has the turbo 350... is this possible out of the factory or has somebody swapped a 350 in for the 400?

There are a few trucks running around with TH350s in them. Whether there were factory ones or not I am not 100% sure.

What's it doing? It's usually pretty easy to pick up on slippage, and a bad torque converter is usually easy to tell as well...

Well at first the guy i got it from said if it was cold then you would have to let it warm up a little and if there was any hill at all then i would have to just floor it and it would barely go... he was right... but with a little fluid and some lucas that helped out a lot... now i have never driven another 6.2, just a 6.5 turbo or two so im not real sure how much power it should have at low rpm but this dosnt have near enough i no that much... if there is a 4x4 wood block blocking my tires... then there is no way im going over... the thing just has no power to get over anything

it dosnt feel like slippage it feels like the torque converter is doing absolutley no purpose at low rpm... im not that experinced at what it should feel like in this truck but it just dosnt seem right...

Ya, you got some thing going wrong in the drive line there. My torque limit system is my drive shafts not objects. 2 front shafts and 3 rear without being abusive. Is it 2x4 or 4x4?

its four

i think somebody swapped tranny and tourqe converter... does that make sense that it would have no power at low rpm?

82 was the transition year from th350 to 700r, i bought a 6.2 truck for parts and it had th350 and it all looked original, and i'm sure it was. torque being wrong can throw off your power. gm was famous for putting in way to tall of gears to get mileage. I had an 81 with a 305 that would barely move, cause of 2.73's. otherwise, does it have original size tires, or has someone swapped them to larger?

your right it could very possibly have the 2.73 or 3.08s and it also has 33x12.50s on it... i guess that could be another variable...

Is there anyway i can check all this? like the VIN or some sort of code somewhere.... and by the way thanks for your help everyone

Not to high-jack this thread, but to those of your higher up on the ladder (ugff...bbbadboy) I think it is time for a 700R4 forum, just for questions like this, we seem to have 1 or 2 a day these days. I know they kind-of go with the with the 6.2, but well they are still popular with other motors, and there are still lots of questions, and answers out there about them.

thanks for the help

google gm rpo codes and check whats on the glove box

i appreciate your help diaric...

no problem, let us know what you find out. high gear ratio, 33.s and engine getting tired would explain a lot. 82 was the first year for 6.2, so the hp was lower then later years

Not to high-jack this thread, but to those of your higher up on the ladder (ugff...bbbadboy) I think it is time for a 700R4 forum, just for questions like this, we seem to have 1 or 2 a day these days. I know they kind-of go with the with the 6.2, but well they are still popular with other motors, and there are still lots of questions, and answers out there about them.

im sorry that im the only one that was talking about transmissions that needed to do this elsewhere... i figured i would get the most help here, didnt mean to crowd the engine forum now

If your transmission has been replaced with a gas engine model with the higher stall RPM converter you could have that sort of issue. In my experience though they usually will still work fairly decent, so I'm guessing there's something else at work.

ya i didnt see it making that big of a difference but when i started reading i didnt really know for sure.... so if i can find an rpo code or figure out the gear ratio then maybe will have some real data to go by...

i think somebody swapped tranny and tourqe converter... does that make sense that it would have no power at low rpm?

According to GM archives, 1/2 ton diesel Blazers, trucks, Suburbans, etc. were never sold with T350 transmissions. That because the 6.2 was created for fuel-mileage potential. The only transmissions offered in civilian 1/2 diesels were the 700R4, four speed manual HD, or four speed manual overdrive light-duty (New Process).

That being said, the early 700R4s had a very high failure rate - and were routinely removed from 6.2s,and either T350s or T400s put in their place.
Some 305 torque converters are the same part # and stall-speed as used in 6.2 diesels.

If you have the standard 3.08 axles, they would of worked fine with the original 700R4 trans since it had such a low first gear. But, when you swap in a T350 or T400, you don't have a low gear anymore. Not so bad in a 4WD since you can use low-range in the transfercase if needed. Not so good in a 2WD.

I've got several diesel Blazers with T400s and 3.08 axles. If I stop on a steep hill -facing up - and have some weight behind me - like a 3000 lb. trailer - the torque converter will just slip. It will not have enough power to make the Blazer move from a dead-stop in high-range.

It's not just the diesels either. There were law-suits brought against GM for gas engine Blazers with 3.08 axles that would not go up a steep hill from a stop in high-range with a full load. Not sure if anything ever came of it.

The 305's with Electronic Spark Control were some of the worst offenders. They were involved in several GM Service bulletins, and a recall. They would "hear a knock" when accelerated from a stop, on a steep hill. The ESC would keep retarding the timing to stop the "knock" until the engine completely ran out of torque and would not move!

The bulletin "fix" was to disable the ESC and go back to centrifugal advance, coupled with vacuum advance. Most early 305 distributors had both. It made the engine run but they would "spark knock" when hot and loaded. Fuel economy was also affected a little bit.

The 700r4 is a overdrive transmission right?

yes the 700r4 is an overdrive tranny... but like you said demaris you have no power with load from a stop... but i have no power with no load from a stop... as soon as i get a new jack im going to try the jack one wheel up and see how many times the drive shaft turns trick... that should get me a little more info... i also noticed that there is absolutley no sign of there being an ovrdrive tranny in there in the first place... is there anywhere else to look for the rpo codes besides the glove box and door?

According to GM archives, 1/2 ton diesel Blazers, trucks, Suburbans, etc. were never sold with T350 transmissions. That because the 6.2 was created for fuel-mileage potential. The only transmissions offered in civilian 1/2 diesels were the 700R4, four speed manual HD, or four speed manual overdrive light-duty (New Process).


My 82 is a civilian non overdrive automatic so they had to have offered a automatic that is not the 700r4

im sorry that im the only one that was talking about transmissions that needed to do this elsewhere... i figured i would get the most help here, didnt mean to crowd the engine forum now

Don't worry, you're not the only one, and this is really the only spot to get, that is why I suggested a 700R4 froum, fo specific help on those trannys. You're not really even clogging up this part of the forum either, we aren't half as busy as the 6.5 guys. I just think it might help guys like you get answers quicker.

My '82 1/2 ton 2wd came with a 700R4 and 2.76 gears. I must have been lucky. I bought it with 30K miles and put another 100K on it. I only did the pump once. The trans kinda failed. The plastic gear on the governer would wear out leaving me with only first gear. I had it rebuilt but it was never quite the same. I hardly ever pulled a trailer.

turns out i have 3.08s so you would think the torque range would be fine at low rpm but its definantly not.... torque converter?

My 82 is a civilian non overdrive automatic so they had to have offered a automatic that is not the 700r4

Well, anything is possible. According to GM archives, none were every sold. I've never seen one in real life either, back when they were new. I went with a fellow mechanic I worked with back in 82 when he ordered his K10 new at the local Chevy dealer and we looked all though all the option packages available. There was no non-OD trans available in auto in 1/2 ton, but the TH400 was available in HD. It was something we were paying close attention too since he'd previously had a 78 GMC truck with the 350 diesel which was a total piece of crap, along with a OD auto that was nothing but trouble.

I also note that many three-speed light-duty transmissions being used by GM in 81 or 82 were turbo 350Cs, not turbo 350s.

I take it you are saying you know, for sure, your truck is all original just as it left the factory? If so, post the RPO code decal. If it shows "LH6" for your diesel along with the M33 T350 trans - than you are absolutely correct. I'd like to see it. If it shows MV4 or MX2, it's not a 350 , it's a 350C. MD8 is the 700R4.

I can tell you this. By 1982, several dealers in my area were not letting any new Chevy trucks leave the door - IF they had a 700R4 trans and a trailer hitch. They would pull out the brand new transmissions and convert to something else - usually a T400. It was a common dealer practice since GM has so many unresolved issues with the new over-drive 700R4.

i also noticed that there is absolutley no sign of there being an ovrdrive tranny in there in the first place... is there anywhere else to look for the rpo codes besides the glove box and door?

Take a look at parts that would of been there and are now not being used for the 700R4. TV cable and bracket, little solenoid to deactivate the lockup converter, wire-harness hookup at the trans, etc. Also, the adapter/spacer between the trans and the transfercase would of been changed and might look a different color or age than the rest. I've got two 83 Blazers here that were both dealer-converted when new, and it's pretty easy to see if you look close. On one, I've got got a T400 with a mechanical modulator (no vacuum hookup). There were mechanical-modulator kits sold just for the purpose of converting from 700R4 to TH400. Mine also has a home-made bracket at the injection pump for the throttle to hit the down-shift switch for the TH400.

i have had the same problem in my 6.2 w/ the banks turbo on it. i have talked to numerous people here on the forums, called people back at home that own tranny shops and friends that have had some of the same problems. the only way i have figured out to fix the problem is to get a rebuild kit, but i havn't had time to get around to it cuz of school and work so as soon as i get it done which should be in a week. i will post on here as soon as i get it done with results.

So i can not find any RPO codes on the truck at all... But I'm almost positive that the truck was an original 3 speed automatic truck... the only thing that ive noticed that looks different is that the vacum hose to the modulater was to short, it had a pretty good kink when i got the truck so i extended it but it didnt seem to make much of a difference. And what is this 350C your talking about?

And to you Jdmaris, im not for sure at all that the truck is all original... the only tags that i can find on the truck at all are the VIN and the little emmisions sticker under the hood and it just says that its a diesel automatic

Hey jimmytd i was thinking about doing the same thing and buying a new torque converter as well... parts are cheap and i know a few tranny shops that will rebuild a 350 cheap so i think ill go that route as well

There's nothing on the back side of the glove compartment door? Cuz on mine it has the stock parts list that came with the truck, which has the gear ratio in the rear end and so on...
I got the re-build kit for the 700R4 tranny at AutoZone for about 120$, which was the cheapest price i could find cuz i'm kinda strapped for money haha.

no theres the VIN and i promise ive looked everywhere on that glove box for some codes but theres nothing

Would a VIN check tell me anything at all?

no theres the VIN and i promise ive looked everywhere on that glove box for some codes but theres nothing

Would a VIN check tell me anything at all?

I've got several 6.2 diesel Blazers and trucks with no RPO decals to be found. I don't know if they never had them, or they're just missing. Some do, and some don't. All my 83s ,85s and 86s have them. One 82 does not and my other 82 has the decal under the hood instead of the glove-compartment door.

Most likely your transmission has a date-code stamped right on it. If the trans is not the same year as the rest of the rig, you can assume someone stuck it in there. After 1967, GM transmission date codes go like this.

Example: P9E03 - (P = TYPE, 9 = year (1969), E = Month, 03 = Day of Month)


Also, if 4WD, there are other swap problems. If the truck came with a 700R4, a T400 won't fit the transfercase - only a T350 will. That because the splines don't match. So, some swappers cheaped out and installed the T350, since putting in a T400 was more work and a different transfercase.

Transfercase shaft has 27 splines to fit a 700R4, T350.

Transfercase shaft has 32 splines to fit the T400 or HD SM465 cast-iron 4 speed (with granny low), and the four-speed manual overdrive trans made by New Process (NP833).

What to you have for a dust-cover at the bottom of the bell housing? Do you have the original cast-aluminum cover with the two steel struts still attached to it? If not, it's been swapped - especially if you have a tin-cover on there.

thanks for the info jdemaris, and ill do some checking on the tranny tomorrow...but there is no flywheel cover there at all... its all open with a blue torque converter... its pretty rough looking as well... but that dosnt mean anything... what gets me is all the linkages are stock looking and the coloum shift would all have to be changed out as well, so if this happened they did a dang good job!

My rpo code sticker says: 1MXO 4-spd. auto. trans

the column does't have to be swapped going 3 to 4 speed and vice versa. swap out the gear indicator, only takes a couple of mins.

and i have an rpo list in my 87 glove box. but on the 81 i had, i remember seeing it somewhere else. under hood, door pillar, can't remember for sure where

thanks for the info jdemaris, and ill do some checking on the tranny tomorrow...but there is no flywheel cover there at all... its all open with a blue torque converter... its pretty rough looking as well... but that dosnt mean anything... what gets me is all the linkages are stock looking and the coloum shift would all have to be changed out as well, so if this happened they did a dang good job!

Many of the conversions I've seen - do not have the original HD dust cover under the flywheel. The original 6.2 diesel setups from the factory use a heavy-duty, cast-aluminum cover with two steel support struts bolted to it. Then run from the dust cover to each motor-mount. If 4WD there is also an additional steel strut fastened between the transfer case and the front of the transmisson where it bolts to the engine. If your struts aren't there, your stuff has probably been swapped.

The strut from the tranny to the transfer case is there but theres no sign of the rest of them that go from the dust cover to the motor mounts

And they also my of swapped out that gear indicator because i noticed the prong that shows what gear your actually in is gone...

..but there is no flywheel cover there at all... its all open with a blue torque converter...

If the torque converter is blue, it may be a sign that the tranny was swapped out, or at least rebuilt, painting the TC blue sounds like an aftermarket thing, not a GM thing.

cast alluminium cover used on other engines as well. my 81 K5 with a 305 had the same cover and supports

cast alluminium cover used on other engines as well. my 81 K5 with a 305 had the same cover and supports

Yes, it's a heavy duty option usually used on 4WDs, gas or diesel. The transmission case is usually thicker also.

i found some more info today when i got a chance... i was busy at the shop and nvr really got a chance to write anything down... but the transfer case is a new process np208 and ill get the code thats written on here tomorrow!