Shift problem

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twayne24365

twayne24365

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While have my motor out replacing he cam, I have another issue to fix, I have a 727 behind the 383 with tci converter, cheetah reverse manual valve body, trans is fresh(used converter) now 1-2 shift is fine, and 2-3 is fine when you shift at wot, but when cruising the 2-3 shift feels like you stab the brake, would this be the band adjustment on the outside of the case? The internal adjustment? Or do I have a bigger problem?
 
That torque converter is your first problem... TCI is junky bro. Especially second hand. Ain't a place to go cheap on..

Did you adjust your bands?
 
Dont think the TC is causing his shifting problem...2-3 shift ...timing of the band release sometime it acts like it is in two gear at once....
 
Yeah that's shift overlap
Either 2nd is not releasing fast enough or direct is coming on too fast. I can't see that as being in the VB. I see that as probably mechanical. The same hydraulic circuit that engages the hi-drum also disengages the KD band. So my best guess is that the hi-drum is coming on too soon, cuz somebody messed with the piston return springs, OR there's something wrong with the KD servo.
Ima gonna go with servo.
So the next thing would be an oil-pressure test.
I guess, since the band adjustment is on the outside, I would loosen it a couple of turns and see what happens.
 
Since the normal adjustment for the band is two turns...I would take it slowly on backing it off...
 
........It also depends on what ratio lever is in it............check to see where it is adjusted to first then loosen it 1/4 turn at a time to see if it helps, if so good, but I wouldn't have it out more than 3 turns,if it has an unkown shift kit in it u may have to take it apart and do some tinkering..............kim.........
 
Thanks guys, I'll try the adjusters when the motors done and if all else fails I'll have to pull the pan and check it out, what I do know is there is no spring in it, when I put the vb in it said not to use the spring, previous owner did say it had a shift kit in it tho
 
twayne24365 said:
Thanks guys, I'll try the adjusters when the motors done and if all else fails I'll have to pull the pan and check it out, what I do know is there is no spring in it, when I put the vb in it said not to use the spring, previous owner did say it had a shift kit in it tho
Click to expand...
In your first post I see you say it's a manual rev valve body. I read here that you say the prev owner said it had a shift kit in it. If someone has tried to install a shift kit into a Cheetah manual valve body they probably messed it all up. The spring your talking about it saying to leave out is for the accumulator. The servo everyone is talking about is what engages the front band.
 
Yes when I bought the car the trans was fresh and apparently had a shift kit, all I did was pulled the pan and put the Reverse manual vb in
 
twayne24365 said:
Yes when I bought the car the trans was fresh and apparently had a shift kit, all I did was pulled the pan and put the Reverse manual vb in
Click to expand...
Since you have the engine out i would pull the trans out and have it gone thru to make sure everything is okay.
 
well I put the engine in and ran the car, I adjusted the low reverse band out a 1/4 turn at a time with no change in the 2-3 shift due to a pump leak I pulled the trans.

what I've been reading says that with a 2-3 shift overlap the front clutch piston springs are too weak and I need to either add more springs, or get stiffer spring, does this sound about right?
 
The L/R band has no effect on the 2-3 overlap.
A leak out the bellhouse can be misdiagnosed as a pump leak, when it can just as easily be a vent leak.
If in fact your 2-3 issue is overlap, and I think it is, Then it may be either a too-tight KD band adjustment, OR, as you are thinking insufficient springing in the hi-drum(front clutch). It could be other things too.
If the tranny whams into reverse at a normal idle speed (750ish), then perhaps someone has removed the wavy spring from the hi-drum. It is there to cushion that N-R shift and also to cushion the shift into hi,by slowing it down at low line pressure,low throttle pressure. With a reverse manual shift kit, this is easy to prove by shifting from Neutral into Direct, at idle. If it whams in, the wavy spring is gone. Sometimes this wavy spring is eliminated during the front modification to install extra plates into that drum.I never do that, cuz I hate that harsh shift into reverse. If the wavy spring is gone, you will need to compensate for that with extra spring pressure.
At this point I should bow out on account of I haven't done a ton of these conversions for other people. During my learning process, that 904(yeah I like 904s) was in and out a lot. I was young and strong and excited to learn this stuff; you may not be....heehee. Plus I had free access to a hoist.And a jack,etc. I don't like RMVBs on the street; but that is a personal thing.I like redheads;and my blond wife is somewhat accommodating.Yeah that's personal,too.
 
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so since it's out what exactly do I need to do...shim the servo so it's solid?
 
Noooo. See what ratio number is on the front lever. U need a minimum of 3.8. I like the 4.2 when using the rmvb. They recommend the 5.0 Make sure u got 2 springs in the front servo if u have a 70 and older tranny. With the controlled load servo u may have to modify it.
 
If you are asking about the accumulator, I have run them several different ways, but I don't like them locked up solid. I put the biggest baddest factory spring in there that I can find, and call it done. I also like the 4.x arms for street.

If it's out, you need to take the clutches apart and check 'em out.And make sure the KD band is releasing and not adjusted too tight(do this first,obviously)
 
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