tranny problems [Archive] - El Camino Central Forum : Chevrolet El Camino Forums

: tranny problems


dezaster
03-07-2004, 09:23 PM
hey guys
gettin the tax return back and tryin to decide what to spend it on.. all in all, the elky has a lot of work to go. but primary things are first on the list and getting the car to move has become a problem.

about a year ago or more, i was driving home on some windy missouri rodes and a bus was stopped around a corner. i hit the brakes @ about 65 and missed the bus (thank God). the motor was running amazing until that point. as well as the tranny. from that point on, i had troubles getting it to shift, downshift, and basically move. it usually won't downshift into first, so, you have to put it into first on the column.. sometimes slips and then it will grab. when you put it into drive it will go into second and it usually takes a magic trick to get it into drive for highway driving.... also, making left turns, the car shudders- i believe this to be a rearend problem? driving down the interstate doin 70 or so with no problems, ya give it some gas and the rpms will jump about 700 then drop to the appropriate rate..

on the tranny, i've replaced the vacuum modulator, filter, fluid.. etc. some have said it was the brake booster, so i replaced the booster and master cylinder and no dice.

this is the 2nd transmission that the motor has 'eaten' and i'm somewhat at a blank. i'm gonna have to do somethin about it so i'm trying to decide if i should stick with the th350, go up to the th 400, or throw a manual into it. the motor is pretty decent, but i don't think it would have enough power to cause the th350 this many problems. any ideas?

and if i have to replace the rearend any suggestions?
thanks, and sorry for the long email,
dez

theelcaminofactory
03-08-2004, 03:02 AM
Concerning the rearend, if it's a 10 bolt and if you've got to replace it, replace it with a 12 bolt complete rearend. Concerning the trans, it's more of personal preference, ease of installation and money issue. If your engine is pretty much stock, a 350THD is fine, a rebuilt one from TCI with a new converter can be bought and installed by you for under $1000, more if someone does it for you. A 400THD will cost about the same, is a stronger trans, but you'll need a shorter driveshaft and different crossmember, adding to the expense! I have no idea why avoiding the bus caused this to your trans, unless maybe you whacked the trans, rearend or driveshaft on something while avoiding the bus, or maybe it was just a coincidence. I suppose it is possible that depending on the specifics you may have done some internal damage to the trans, bent a wheel, the axle housing, axle flange, the driveshaft, control arms or even the frame during the incident, especially if you slid sideways...hard! I don't think this would cause your trans to slip and/or not shift however. Sorry I couldn't be of more help.

dezaster
03-08-2004, 08:09 AM
thanks for the reply..
avoiding the bus only involved a complete lock up of the brakes... nothin more, no slide or anything. i was pretty dumbfounded myself. that's why i changed out the power booster and master cylinder. eh, i'm just a guy tryin to figure it all out :cool:

the motor hasn't been dyno'd, but it's far from stock, so i don't know how many horses i'm puttin it through.. um.. i rebuilt the motor about 3 years ago- specs:
bored 30 over
flat head pistons
305 heads
competition cam
edelbrodk 600 cfm
hei....
don't exactly remember everything else

with the tranny, should i opt for the rebuild or just buy new?

ElkyPete
03-08-2004, 11:22 AM
hey guys driving down the interstate doin 70 or so with no problems, ya give it some gas and the rpms will jump about 700 then drop to the appropriate rate..

on the tranny, i've replaced the vacuum modulator, filter, fluid.. etc. some have said it was the brake booster, so i replaced the booster and master cylinder and no dice.


dez

This sonds like a Torque Converter issue, the part where you stpe on the gas and it revs up then slowly goes back to normal. It is actually not engaging the converter its trashed inside. Probably the reasin this transmission is not working properly either.

I'd say, just guessing, that you need to replace the torque converter and clean out the transmission really good before you put it back in service. When the torque converter goes it leaves trash in the transmission so it will need to be cleaned up.

I'd almost bet that is the sole issue is that torque converter.

But then I could be wrong, I don't think so.

dezaster
03-08-2004, 11:41 AM
after doin some research, i was leaning towards the torque converter as well, but never could connect how it would effect the shifting and such... how bad do these things get? and will a flush of the tranny get all the junk out?

i was planning on purchasing a torque converter anyways, will just make more sense to me now 8) would be nice to save the money on a new tranny as well

Mrapii
03-08-2004, 01:46 PM
You might have a bad torque converter but I'm guessing that your trans needs a rebuild. I can't see any way that locking up the brakes to avoid hitting the bus had anything to do with your trans problems--probably just a coincidence.

bgstk
03-09-2004, 08:08 AM
Assuming it's a bad torque converter, which I'm inclined to agree is probably the problem, you have to remove the tranny. I definitely would not just flush the tranny and hope to get by with it. Rebuilding a TH350 is not an expensive proposition and I would not replace the torque converter in this situation without rebuilding the tranny. Remember, if there's still debris in the tranny after the flush, which is certainly possible, you may very well ruin the new torque converter.