turbo 400 ????

[Alky V6]

Thanks Chris for explaining that. I was wondering what sort of advantage there could be by going to an inferior synchronized style shift with a 400.

 

[Alky V6]

Thanks Lonnie for the explanation. So I take it the rearend let go and the engine went to redline, overspeeding the direct drum. What in the sprag assembly let go? It let go without the intermediate clutch being applied?

 

[quickt]

Thanks Lonnie for the explanation. So I take it the rearend let go and the engine went to redline, overspeeding the direct drum. What in the sprag assembly let go? It let go without the intermediate clutch being applied?

I am not sure what happen I was not there but I do assume you are correct.
The snap ring came loose spread apart like it was stretched out with snap ring pliers. Not sure how if you have seen the snap ring that was used. Looks like outer race tried to walk off of drum and caused damage to the sprag cage and inner race. The inner race had some slight spike marks not sure if caused from over speed or normal shifting but you could catch them with your finger nail. Same with the outer race. The was no issue with the hardness of either you could not even scratch with a file. Still drum could no longer be used with a sprag. The inner race did come right off after the plazma cutter took out the retaining pins.

 

[quickt]

I was wondering what sort of advantage there could be by going to an inferior synchronized style shift with a 400.

Simple Answer You sometimes have to go back to go forward. You call it inferior. The guys who use them and win races and championships call it genius. I am out we trampled this guys thread to death. Don I am sure you will want to debate this forever so you can e-mail me direct. lonnie@extremeautomatics.com

 

[Alky V6]

Ahh. That explains why they're tacking the snap ring in place now. Sounds like the same problem the AODs were having with the intermediate roller snap ring. Centrifugal force spreading the ring until it comes off.

 

[jakeshoe]

Why not use the double wound spiral rings from a 4L80E? I'm sure there's more to it, because I know Lonnie and others know this trick.
I never tack weld on a TH400 retaining ring anymore.

 

[Alky V6]

Sam. If you don't mind me asking, do you have any idea what the max rpm the engine might have hit when the rearend went on you at the starting line?
If it hit a rev limiter, what was it set at? Thanks.

 

[Alky V6]

I agree with you Jake. There has to be a better system to retain the sprag assembly than tacking the snap ring. Don't know what that might be at the moment, but if that is the only way this sprag is failing, then it seems silly to me to throw out the whole idea because of a simple retaining snap ring problem.

The snap ring is very thick. Maybe double or triple spirolock snap rings?

There's some smart tranny minds on this board. I know someone can come up with a way to fix a simple snap ring problem.

 

[blackplague]

on a high rev-er

Why not use the double wound spiral rings from a 4L80E? I'm sure there's more to it, because I know Lonnie and others know this trick.
I never tack weld on a TH400 retaining ring anymore.

They spread too and pop off. Ask me how I know. It's got to be a gorrilla of a snap ring (like a super high tension c-clip) or Tack with a liitle si-bronze.

 

[Alky V6]

They spread too and pop off. Ask me how I know. It's got to be a gorrilla of a snap ring (like a super high tension c-clip) or Tack with a liitle si-bronze.

That must be what was used to tack the last drum I got. The tack was an off color. Not a normal steel material tack. I'm sure a much lower melting temp.

Yes. I've heard of spirolocks popping off too.

What about a retainer to retain the snap ring, similar to how they do it with the AOD?

 

[Alky V6]

No need for debate Lonnie. I know enough about transmissions to know that a synchronized shift will never be more efficient than an overrun shift.

Now from a durability stand point alone, it is always preferred to do away with sprags at any possible chance. But, if the only weakness is the retaining snap ring with the new super sprag, I don't understand why everyone is throwing to whole idea under the bus. Come on guys. A snap ring problem? I already have multiple ideas of how that could be taken care of.

I'm wondering. How is the spragless assembly retained to the drum? A snap ring? Better not be.

 

[blackplague]

Crazy!!!

That must be what was used to tack the last drum I got. The tack was an off color. Not a normal steel material tack. I'm sure a much lower melting temp.

Yes. I've heard of spirolocks popping off too.

What about a retainer to retain the snap ring, similar to how they do it with the AOD?

I thought Griner was out of his mind about the spiroloc snap rings popping off, till i encountered one of mine that poped off at 7500 rpm + ( winner of last year's all motor lsx shoot out's car). The nice thing about si-bronze (slight gold/bronze color) is that it grinds super easy for servicability of the sprag.

No retainer to retain the snap ring like the aod/aod-e - just the 4l80-e intermediate roller/sprag clutch spiroloc ring.

For the monster rpm's application I just tig w/ si-bronze the snap ring to the retainer plate. I'm not trying to be a cheap skate, i just don't want it to pop off.

 

[jakeshoe]

Don,
The spragless setup is a complete drum assembly made with the intermediate clutch race as part of the drum.

Mike,
I've had TH400's at 12,500 rpm in monster trucks with the 4L80E ring...

I've seen the TH350 snap rings come off in Bonneville Salt Flats trans at ~8000 or so. So I use the spirolocks on them now too, but the ones I use don't have the "tangs" like the GM 4L80E piece does.

 

[chris718]

there is a rigid od retaining ring with two eyes that fits right in here and never comes out.it isnt easy to get in,you need a real heavy duty snap ring pliers like the ones used to remove the pinion bearing retaining ring on the old 413 chrysler,but that is an external ring.i also put a rubber band around the tips so the pliers becomes spring loaded.Don the outer race is bolted to the drum.

 

[blackplague]

Wow

Don,
The spragless setup is a complete drum assembly made with the intermediate clutch race as part of the drum.

Mike,
I've had TH400's at 12,500 rpm in monster trucks with the 4L80E ring...

I've seen the TH350 snap rings come off in Bonneville Salt Flats trans at ~8000 or so. So I use the spirolocks on them now too, but the ones I use don't have the "tangs" like the GM 4L80E piece does.

I'm suprised the drum didn't explode at that rpm. Is that a stock drum?

I don't know what happened to that 4l80-e ring. The day griner was telling me that about the 4l80-e spirolock, i was tearing that unit down, and SOB it popped off. I thought griner had a crystral ball. The trans was still working in all gears.


You back on land?

Mike.

 

[blackplague]

That's the ring I'm talking about.

there is a rigid od retaining ring with two eyes that fits right in here and never comes out.it isnt easy to get in,you need a real heavy duty snap ring pliers like the ones used to remove the pinion bearing retaining ring on the old 413 chrysler,but that is an external ring.i also put a rubber band around the tips so the pliers becomes spring loaded.Don the outer race is bolted to the drum.

That ring is a real gorrilla to get on and off for sure.

You feeling better yet?

 

[Alky V6]

Why not use a thin plate similar to the ZF stuff. The plate goes on, then the snap ring and then the plate is bent up against the snap ring at four spots to retain it.

I'm going to look into the si/bronze rod. Sounds like a simple solution.

 

[jakeshoe]

Ya,
I'm back.

Stock drum, TH400, 10,500 lb Monster truck, ~1400 HP 8-71 alcohol injected 509 cid BBC.
I've seen it kill low roller clutches so bad that you can't pry the planets apart.

Going off memory here but it seems like Art Carr was building them at the time and they were only lasting about 3 weekends before they let go. Maybe someone remembers if Art Carr was in Reno, NV at the time? This was back around 96-97 timeframe.

I pieced one together from the blown up unit in the truck, the spare that was also hurt, and a core I had laying around on a Saturday night.
Won the finals the next day

I didn't know shyt back then either, if you had asked me what a reaction carrier was I wouldn't have known it by name. I had assembled a dozen or so TH400's and that must have been pure luck more than skill.

I remember it had waffled plates in the spare, stock tans in the one that let go.

I think he is having Len Freeman do them now in LV and they are holding up.

They went to a 572 combo also, so may have lowered the shift rpm.

 

[INTHEEIGHTS]

I called you were gone.

Wow guys.I leave for a day and come back 20 post later .Thats why i like this board so much cause it has a wealth of knowledge and a bunch of good guys.........

 

[INTHEEIGHTS]

I need to call you, wish you were closer I have a 400.

Whats up john. What do you have for a 400.Take care we need to talk. Called a couples times.