Ok, say what you will, I know this isn't exactly "traditional" talk but I really need some advice concerning my th350. So I made the swap to 350/350 combo (sbc 350 and th350) and I've thrown in 3 different trannys, with no success. Either I have awful luck, or it's not the tranny's that are the issue. Now an acquaintance has brought to my attention that if the transmission is not installed sitting relatively level in the car, the pump inside of the transmission will not operate properly. Now I had not considered this before, but it sounds like a resonable theory. I know there are many variables to this problem, I'm trying to deal with one problem at a time here. My question here is: Is installing the transmission level in the chassis essential to having it work properly?
Every car I have owned with a TH350 seems to go up and down hill with out a hitch. The trans. is not level when doing that. How far off of relatively level is your trans. in your car? What is failing on them? The pump will work if it has fluid to pump.
i think you'd have to be pretty far out of level to the planet to have an issue caused by a fluid level situation (pickup not submerged). level to the car only maters if the car is level to the ground. - however are you running a deeper pan without a spacer or longer pickup? -rick.
It doesn't matter if it's level or not. It does matter that the fluid level is right though. Have you disconnected a cooler line to see if you are getting pressure? Are you putting enough fluid in? If it's full of fluid and you are getting pressure out of the cooler lines then it should do something. If it's full and you don't have pressure then you could possibly have broken the pump gear by not having the converter in all the way when you tightened the bell housing bolts. Are you using a different converter with each trans?
Alright, so my good friend, Stacey figured out my problem! And thought it was worth posting in case some other poor soul runs into the same problem... What was the problem you may be asking yourself. Well apparently the torque converter was not going far enough to make contact with the front pump tabs. So I stacked washers in between the flexplate and torque converter to bring the torque converter closer to the front pump. Well I stacked washers so that the converter was bottoming out on the pump (not good) but it did get the pump to pump and go into gear like it should, great. So I took out some of the washers, put it back together and it's not engaging. So I still have to find that magic area so it's forward enough to not rub on the front pump, but far back enough to where it makes full contact with the tangs on the front pump. Now why I'm having this problem, Possibly a different style flexplate, though I doubt that. Anyway, wanted to share this.
If its that fussy about location you have something broken in my opinion. They usually go back a good ways clear of the flex plate and get pulled forward to allow bolting up. I've never seen one THAT particular about placement!
I agree that you shouldn't need washers in there. You have a wrong part somewhere in the mix. If you are using washers as spacers, they might not be consistent thickness. Also, you may not have the center register hub fully into the hole in the back of the crank. Sounds like a possibility for wobble-City.
It is not uncommon to use washers to obtain the proper clearence between the transmission and engine you should have a minimum of .060" not more than .100" clearance, push the converter back all the way and measure the clearance between the converter pad and the flywheel this can not be tight as it will take the thrust bearing out of your engine or damage the pump in your transmission. Torque converters are assembled with a height to pad measurement called stab depth unfortunetly there are many torque converter remanufactures that don't have that information or ignore it. If a converter is not installed correctly three steps (Input shaft, Stator shaft to converter stator, and pump to drive tang) it will chew away at the drive tang and have the problem you are experiencing. The picture on the top illustrates new pump gears the one on the bottom the tab is half worn off due to improper clearance between converter and flywheel or improper assembly not having the three steps. Normal flat washers are about .060" thick I would not use more than two equall thickness washers per pad to shim a converter.
My thought is something is eskew with the torque converter. I think that because it seems to me most GM flex plates are similar in thickness. How many washers are you using...do they add up to an 1/8 inch or a 1/4 inch? I agree with alchemy in that there is a wrong part some place. tim
I think OldFord39 is getting you on the right track. Also, look at the drive lugs on the inner pump drive gear in the picture above. They're offset toward one face of the gear. I don't know if the picture above is for a TH350, but is it possible that the inner gear on your pump was installed flipped over the wrong way? Check your pump and then find out for sure which way the inner gear is supposed to be installed.
Transmission troubles not solved. So after 3 transmission changes, What stayed common to all 3 ? That will help you narrow it down. It's hard to think all 3 had the same internal fuck ups. Did the same converter go in all 3 ? That may explain it and point to a converter issue.
My 700r has the tail shaft down 3 degrees and my pin on up 3 degrees. This causes the u-joints to work and reduce vibration. Get a transmission buddy over there to look at the converter. This sounds like a break down in the most unexpected place. Posted using the Full Custom H.A.M.B. App!
Well, I pulled the trans out again, pulled out the pump. Seems to be fine... After taking the front pump off of the transmission I set it over the top of the torque converter just to see how it set on the pump and everything seemed right... I'm gonna sleep on it, stare at it for a while longer, have a beer and see if I can figure it out. If anyone has suggestions, I'm welcome to hear it.
I can see on the gear where the torque converter snout was barely touching it. I'll take a picture of that for you guys to see later.
Some race cars have the converter snout changed when the converter is built. The mid plate mounting system is frequently 1/4 thick and so spaces the trans case further away from the trans.Most converter companies will account for this in the mounting tabs.
Well on the level thing, I think that as long as you are checking your fluid with the transmission out of level you should be fine. I don't know what your problems with transmissions are or where you are buying your transmissions so I really can't answer your question very well. Too many variables here. I am not sure I understand, I have been doing this for a very long time, like well over 40 years long time (closer to 45 I think). Granted my memory is not as good as it used to be but I don't recall ever shimming a converter in a stock application.
Blacknred, that's actually a great question. I'll check to make sure. Another thing to consider was I was using the http://www.summitracing.com/parts/sum-g2699/overview/ I am now going to put in this torque converter http://www.summitracing.com/parts/ape-47000/overview/ Both are advertised to be stock stall ratings.
WRONG TRANSMISSION altogether... I had a 350 C, which apparently is totally different. I was told it takes a completely different torque converter. No wonder it didn't work! Oh well, lesson learned. Btw, for future reference for anyone else who might run into this problem, the 350 C transmission has a 4 prong female electronic plug (or at least mine does) on the passenger side of the transmission.
... and I've thrown in 3 different trannys, with no success. 3 different transmissions, & all 3 of them were 350c
That remains a bit of a mystery, the only thing I can think of is wrong torque converter. I know one of them had a bad pump. There was the 350C. And I think the first one I put in worked, but there was some issue with it that started this whole mess. I really think it was the wrong torque converter.
Definite difference between converters. The TH350C has a lock-up clutch in it. Big difference in the trans input shaft as well. Don't imagine that the regular TH350 converter will properly engage the 350C input.
This is exactly what I was looking at on my bench with the two transmissions side by side. I put in the torque converter, pulled it out 1/2 from the edge of the bellhousing (the distance the flexplate comes out from the edge of the block where the bellhousing bolts up) and it slid back perfectly into the splines. On the 350C the torque converter didn't go far back nearly enough... I feel so stupid, but now I know! Hopefully someone else will read this and not have to go through all the trouble I did.
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