Transmission Guru's Help needed

[oldblue116]

Watching this one

 

[TheWanderer]

I can't imagine how frustrating this is for you, I've read through every single post, but I'm going to still say the problem is the converter.

The reason I'm saying converter is as follows:

- The car only weighs 4,000lbs, even a lightened up truck will typically be 6800+. The way that vehicle weight, axle ratio & tire height affect stall is something a lot of guys can analyze and discuss to death.

- The V10 converter is still a 310mm (13") Borg type converter. Even if the stall has been raised by machining the stator and/or bending fins, you're still dealing with an insane amount of mass and a converter that is still a very close cousin of it's diesel counterpart. Lets say you wanted it to stall at 2,400RPM for launch purposes or approx 1,000RPM over stock. In a typical converter, to gain 1,000RPM, you can NEVER do it by just machining internals, the diameter of the converter has to get smaller in diameter. As a rule of thumb, one inch of diameter reduction will typically increase stall speed by around 500RPM. Of course, since you're dealing with an RH and a Cummins, you can't really reduce the diameter without a different flexplate allowing you to run a gas converter (which is going to be too weak lock up wise for you) or some sort of hybrid converter using a smaller diameter top, which would look something like this (this photo is for illustration purposes only):

So by reducing the diameter of the top to say an 11" will likely give you the idle & launching quality you're looking for, but of course, it's going to couple less efficiently and be looser until it's in lock up, so a launch sequence would have to be: roll into staging lights, spool turbos for launch, take off and engage lock up all during the 1-2 shift and finish the track in 4th/lock up.

The biggest challenge here is that you need get someone to make you a completely custom converter like that with a smaller diameter pump and a custom stator while allowing you to retain the larger clutch, it's going to be a challenge and costly.

Anyways, I don't claim to know everything about everything, I'm not perfect and I could be wrong, but, what I can tell you is that the only way you're going to have a zero stall condition is either the converter is spragless or the sprag has flipped in it's race, both are rather unlikely at this point.

If you had even a partial TCC apply condition, created by a leak, you'd have burnt forward clutches in very short order since they would be spinning all the time, including at an idle.

The problem you have here is that you're in completely uncharted territory with a car like that...

 

[oldblue116]

Very Very interesting^

 

[12vriviera]

I don't see how the weight of the vehicle affects stall sitting still on the line.
A 7klb truck vs a 4klb car should spool the same on the line if they used the same setup.

 

[TheWanderer]

I don't see how the weight of the vehicle affects stall sitting still on the line.
A 7klb truck vs a 4klb car should spool the same on the line if they used the same setup.

IF it had a trans brake, I would agree, however, it does not. It's relying on the cars own weight and brake ability.

 

[12vriviera]

He said he has 2 calipers on rears and singles on the front, it had more brakes than anything i have driven.
Rich Buckley is using a standard diesel converter, hell lots of people are in a light vehicle.
So sitting at the line with brakes on, weight is not an issue in getting it to spool.
It is something else,

 

[TheWanderer]

OK, if you guys say so. Just trying to help.

Why not borrow/throw in a completely different, bone stock unit just to see what happens?

 

[SHughes]

I see what you're saying Wanderer and can certainly apprieciate the help and insight...I just don't know how it could be the TC after as many as it's been through. I hear wht you're saying about it pointing to the TC, but in my limited experience with Dodge transmissions at high power levels not everything goes as expected. I've had a few issues that no one could explain...even a similar issue and I never got an explaination of how it was fixed.

If you were to have ruled out the TC at this point (hypotheticaly) what would be your next step? Where wuld you look next?

Epically post by a dumb phone.

 

[TheWanderer]

Well, the only way you're going to have a zero stall condition is if the lock up is applied or partially applied, which like I say would burn the forwards up very quickly. To do that, the pressure regulator valve has to send oil to stroke the switch valve and the converter clutch valve has to be stroked.

As far as I am aware, both of these have been addressed, have they not?

Now back to the thing about the input shaft, which was why I asked about it pulling forward in neutral and since it's the only original part left and could be easily overlooked, and as noted the converter isn't charged in park... UNLESS it's been shift kitted, which it probably has......

 

[12vriviera]

See that's interesting...
But it would for sure bind in reverse and not move and actually drive the vehicle forward in neutral right?

 

[TheWanderer]

See that's interesting...
But it would for sure bind in reverse and not move and actually drive the vehicle forward in neutral right?

Well, it would if the converter wasn't charged, but since most shift kits drill the PR passage to allow converter charge in park and mask 'drainback', that circuit is now open, so what's to say it isn't sending that oil to the converter clutch instead..............

 

[BowtiedCTD]

If it was cracked, it would likely be the same conditions (pull forward in neutral & bind in reverse) since it would have the same leak to the TC piston.

I want to touch on this a little bit: "The dyno would be the engine dyno's that "G" uses to "test" their producs. If the conveter stalled on a chassis dyno why would it not stall at the track?"

If I'm understanding you correctly, no converter has ever stalled correctly in this car, correct? But have worked in trucks, correct?

Goerend has 3 dynos, an electric load cell, a converter, and transmission dyno. THe load cell is designed to run a converter and transmission combo to test them to make sure they are working properly. They have a second dyno that is an inline six that test stall speeds on converters with a transmission that they built for said dyno. Then they have the third that is a small block chevy that has a perm mounted converter plate for varying converter/trans setups. They test the functionality of the transmissions on this one as far as shifting through the gears and proper line pressures. our transmission and converter were supposed to be put on the electric load cell dyno as a paired combo to test the stall and trans but never were. The converter passed their converter dyno and the trans shifted and line pressures tested ok on the 3rd dyno. THEY WERE NEVER TESTED TOGETHER ONLY INDIVIDUALLY.


The nuetral issue you speak of is actually a cross bleed issue that will happen if the VB or cracked case is trying to apply more than one clutch pack at the same time... This happened when the "G" VB had a cross bleed between circuits 2 and 3. They rebuilt VB and that went away but the instant into gear is still present. Which is why the last two builders I have talked to are pointing at the case or the input shaft but they are leaning heavily on the case being phucked.

I can't imagine how frustrating this is for you, I've read through every single post, but I'm going to still say the problem is the converter.

The reason I'm saying converter is as follows:

- The car only weighs 4,000lbs, even a lightened up truck will typically be 6800+. The way that vehicle weight, axle ratio & tire height affect stall is something a lot of guys can analyze and discuss to death.

- The V10 converter is still a 310mm (13") Borg type converter. Even if the stall has been raised by machining the stator and/or bending fins, you're still dealing with an insane amount of mass and a converter that is still a very close cousin of it's diesel counterpart. Lets say you wanted it to stall at 2,400RPM for launch purposes or approx 1,000RPM over stock. In a typical converter, to gain 1,000RPM, you can NEVER do it by just machining internals, the diameter of the converter has to get smaller in diameter. As a rule of thumb, one inch of diameter reduction will typically increase stall speed by around 500RPM. Of course, since you're dealing with an RH and a Cummins, you can't really reduce the diameter without a different flexplate allowing you to run a gas converter (which is going to be too weak lock up wise for you) or some sort of hybrid converter using a smaller diameter top, which would look something like this (this photo is for illustration purposes only):

So by reducing the diameter of the top to say an 11" will likely give you the idle & launching quality you're looking for, but of course, it's going to couple less efficiently and be looser until it's in lock up, so a launch sequence would have to be: roll into staging lights, spool turbos for launch, take off and engage lock up all during the 1-2 shift and finish the track in 4th/lock up.

The biggest challenge here is that you need get someone to make you a completely custom converter like that with a smaller diameter pump and a custom stator while allowing you to retain the larger clutch, it's going to be a challenge and costly.

Anyways, I don't claim to know everything about everything, I'm not perfect and I could be wrong, but, what I can tell you is that the only way you're going to have a zero stall condition is either the converter is spragless or the sprag has flipped in it's race, both are rather unlikely at this point.

If you had even a partial TCC apply condition, created by a leak, you'd have burnt forward clutches in very short order since they would be spinning all the time, including at an idle.

The problem you have here is that you're in completely uncharted territory with a car like that...

I doubt you have read every post on this thread thoroughly. You have missed the fact that the second converter stalled until we fried the transmission due to the TV cable becoming disconnected mid run. Since then no matter what brand or stall converter the transmission has refused to stall.Also the last two converters have been cut apart by different manufactureres and found absolutely nothing wrong with the converters and could have not been rebuilt because they didn't need to be.

As far as blaiming the 13" converter that is bogus as Garrett ran the same "G" converter in his pulling truck and it stalled just fine. Made a lot of passes and I don't remember him ever having this issue and made about 500HP more than our setup does. Phil runs the same converter he builds and launches over 2500RPM iirc and hasn't had an issue that I know of to date.

Weight does not have an affect on stall until its starts engaging, which should be around 2500rpm when the converter starts to come into enough flow to couple the converter. Only until then should the brakes and weight fight against the converter. If this was true you would not be able to test converter stall outside of a vehicle. When we had the "G" converter that would stall NO BRAKES were needed between idle and 2500RPM as the converter is not engaging and trying to move the car until those RPM and wont full finish stalling until 3000RPM. This was particularly fun when loading the car on a steel trailer in the snow.

This isn't really uncharted territory as there are many guys running high stall converters. We have also had issue frying clutches as well in either the OD or forward pack, I can't remember for sure.

You also seemed to miss the part of me driving 9 hours round trip to pickup a known to be good 47RH to put in the car to see what happens.

IF it had a trans brake, I would agree, however, it does not. It's relying on the cars own weight and brake ability.

It's actually relying on RPM to stall the converter.

He said he has 2 calipers on rears and singles on the front, it had more brakes than anything i have driven.
Rich Buckley is using a standard diesel converter, hell lots of people are in a light vehicle.
So sitting at the line with brakes on, weight is not an issue in getting it to spool.
It is something else,

The car has 4 piston calipers at all four corners coupled with hydraboost, brake pressure should not be an issue.

And yes, this is completely frustrating as we listened to the so called experts and have spent enough money to build a second trans in the efforts to attempt to fix this one transmission. Almost to the point where it goes back to a gas engine and a blower.

 

[TheWanderer]

All I can say is I feel your pain...just trying to help... I think I have a spare case here, but the freight would likely be ridiculous on an item that large from the frozen tundra to you...

 

[joefarmer]

IF it had a trans brake, I would agree, however, it does not. It's relying on the cars own weight and brake ability.

You're exactly right. In a 4000# s10, a converter built for 3300 stall in a 8k pulling application stalled around 1900. Backed the timing off a little more and it stalled at 2200, but didn't have any power in the top end of the track. Weight matters. I can't explain why.

 

[DieselWrencher]

You're exactly right. In a 4000# s10, a converter built for 3300 stall in a 8k pulling application stalled around 1900. Backed the timing off a little more and it stalled at 2200, but didn't have any power in the top end of the track. Weight matters. I can't explain why.

I thought this the entire time I built this car. I would say weight is the problem, but once upon a time, we had a 2500rpm stall until the TP cable came off and smoked the forward clutches. Ever since that time, no more stall. So, it can stall, just have to figure out WTF the problem is. We're going to stick a different trans in the car, and swap all the internals from my trans that is in the car now and put it all in a different case. It'll have Goerend's VB and Goerend's 3k stall. It'll be going in a crew cab short bed chevy and we'll see what it does.

 

[TheWanderer]

So what ever happened with this thing?

 

[DieselWrencher]

So what ever happened with this thing?

We swapped valve bodies with no change. We ran the car the way it was and the plan is to swap the case out some time and see what happens. When it's torn apart we'll check the input shaft, but I highly doubt it's cracked. If it is I'll be pissed. It's only ever seen 4 hard launches with 20psi. I know that is nothing for these billet parts at this weight. It sure would be nice to figure out what it's issue is. Still has no stall at all.

 

[DieselWrencher]

My brother pulled the trans back out last week, and we tore it apart yesterday. We found more burnt clutches and a few way loose clutch packs. This trans had maybe 10 1/4 mile passes on it since we got it back from Goerend. A big thanks to them for doing quality work................................

Now we are switching cases, crack checking the input, and rebuilding the trans so we can see if we can get the car to stall again.

 

[BowtiedCTD]

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The car has only had 7 passes on it since the last rebuild by a supposedly good builder. This isn't the first time they built it and its burnt up the forward clutch pack. We were trying to make it for a TNT this weekend since we thought it was only going to be a swap the guts into a new case but now that its a full rebuild its going to delay us.

I do have to thank Darren at Pro Street Diesel for the time he has put into helping us try to diagnose this pile of transmission.

 

[BowtiedCTD]

Found out today the transmission was never built properly, direct drum piston only had 9 spring in it causing the piston to engage prematurely burning the clutches and not causing the temps to rise. Thanks Goerend, definitely top notch quality work.