Can anyone figure this out (th350 sluggish)

[tmills213]

Guys (and girls)

I have recently installed a 383 and th350(w/ transbrake, reverse manual valve body) from a close friend. He had built it from ground up for a chevelle but it ended up sitting for a while(few yrs). I did not rebuild the carb as they had occasionally started it to ensure seals and everything would not rot out and it sounds healthy.

I tried taking it for a test drive and it seems to have no balls to it. It will shift 1 to 2 and chirp the tires and fine from 2 to 3 as well but seems like it is in a low gear and will act like it is engine braking at about 50-55mph. More recently I notice (before i had the transbrake solenoid hooked up) that N to 1 is giving a harsh metal clunk sound. thought it was maybe the solenoid flopping around but now that it is hooked up i have no idea whats wrong.

I changed the trans oil and filter today, very dirty from what i am guessing was the initial break-in? (i hope)

It is in a 64 c20 camper special. It isnt turning into the tire burner I anticipated. Anyone have any ideas????

[GMR-PERFORMANCE]

There looks to be a large piece of metal laying there to the upper LEFT of that pic...

you also have large chunks of ..what may be plastic.. govener gear maybe.. ... but if that shreds they most times will not shift out of second but it may be starting to go..

[tmills213]

The thing that is confusing me the most is that it seems like I can shift it through all the gears fine. maybe i am missing something that you meant. I dont know much about these things

[clinebarger]

Your running a reverse manual valve body with a Trans brake on the street in a 3/4 ton pick-up? And im guessing a 3000+ rpm stall converter?

Using drag race stuff on a C20 pick-up doesnt sound right?

[GMR-PERFORMANCE]

Right or wrong set up for the job does not change the fact its clanging on the up shift, sprang, maybe with an auto its hard to tell , you can try a trans shop and have them do a few pressure tests, but if there is metal you are going to take it apart anyways, may as well save the money
Take your time with the filter and sift through the items on it.. Metal chunks is a no go.

[clinebarger]

Originally Posted by GMR-PERFORMANCE

Right or wrong set up for the job does not change the fact its clanging on the up shift, sprang, maybe with an auto its hard to tell , you can try a trans shop and have them do a few pressure tests, but if there is metal you are going to take it apart anyways, may as well save the money
Take your time with the filter and sift through the items on it.. Metal chunks is a no go.

The fact is. His Trans will not last long on the street with the manual valve body/Trans brake. A big heavy truck will just make it burn down faster.

Manual valve bodies have "Constant" line pressure. So a pressure test will tell nothing..except it has really high line pressure.The trans doesnt shift automatically so the governor gear being stripped doesnt matter.

The high line pressure, Window shattering shifts & accidentally taking off in 2nd or 3rd is what makes maual valve bodies on a street vehicle a BAD idea.


tmills213...Have a different TH350 core built for the street.

[truckdude239]

its time for a rebuild with that much metal

[GASoline71]

Yep... if any of that crud got in the TC... it's gonna have issues too.

Gary

[tmills213]

Should I just try and clean out the valve body first or is there anything i can inspect before going full out rebuild? There was a few pieces of metal pretty decent size but most of what you see is a weird plastic goo? not sure what it is. There was a lot of clutch dust in the bottom. What am i looking at for a rebuild (cost, time, do it myself?)

thanks guys

[GMR-PERFORMANCE]

PM sent

[GASoline71]

The TH350 was probably the most mass produced transmission that The General ever made. So parts and rebuild kits are pretty inexpensive.

Gary

[GMR-PERFORMANCE]

One more thing on a t350 with trans brake it MUST have a billet hub as they are a cast hub from factory. Use of a TB with a cast hub will end with a trans with holes in the case for the most part. Ask me how I know LOL.. I was running a el cheapo drag car and tried that.. it did not last long and the engine was not a killer set either. T400 comes stock with billet hub vs cast. As well with a trans brake a anti balllon plate on the convertor is a very good idea.. Not knowing much about the parts that are in the trans less sturdy convertors can ballon up if the brake is used and end up busting the pump..

Slim chance but never the less broken parts are broken parts.


As for cleaning out the trans.. not going to work if something is broken. Pull the trans have a shop go through it. Your job is flushing the lines and cooler until its ultra clean.

My question is that set up was said to me new, and for you just starting to drive it there is a ton of crap on the bottom of the filter.. To me its either a burnt trans all ready or it was not as new as your where told.

[tmills213]

As far as the trans brake goes i would pretend it isnt there. I dont really plan to use it, it just came with it and wanted to let you guys know. I am in the wishful thinking stage right now but there isnt anything else it could be is there, Driveline, reareend? Im pretty sure these would be toast if it wanst the trans.

[cableguy0]

With that much material in the pan just accept it and start yanking the trans. If you work quick it can be on the floor in about 20 minutes.

[tmills213]

Im trying to suppress the idea of pulling but it is pretty strong. there isnt a vacuum line or anything i am missing or governor bad or idk. I am sure you are all correct.

[cableguy0]

There is no vacuum line because its a full manual valve body. The governor means nothing to that trans either. The governor controls shift timing in an automatic. Basically your transmission is no longer an automatic and cannot shift without you shifting it. It doesnt need the modulator or the governor. If its having issues they are 100% internal.

[cableguy0]

Just to add my bet is the low gear sprag that sits in the bottom of the case is in pieces and turned in the case. Even though its a full manual transmission you still should never downshift into first gear while driving down the road. It will rip the lugs right out of the transmission case and explode the sprag.

[tmills213]

Like I said, im in denial stage and being dumb. Thanks for the help, I appreciate it very much!! I would still be scratching my head not getting anywhere

[cableguy0]

I have broken or blown up no less than 8 th350's in the last 12 years. Most of those happened within 3 years. A lot of it was broken hard parts due to me driving like an @ss. A couple were random failures. I learned quickly that good parts cost money and are well worth it. A good torque converter is an absolute neccessity. Im not talking about the garbage ebay specials or the B&M junk. You need to be looking ATI,Hughes,yank etc. Expect to spend 600 or so for a good converter. You need an anti ballooning plate at a minimum as far as converter upgrades go. Yank the unit and take it to a reputable builder.