The Dodge Challenger Message Board

The current TF 727 has broken.
I try to rebuild it but I don't want to break it again, I look for a friend with a lower torque engine who wants it.
This unit is a reinforced hughes 727, but I keep the converter, it's a 9.5" dynamic custumized.
I like Turbo Action but it's expensive, anyway I need some tranny which could handle about 600 lbs of tq.
Forward pattern, full automatic, race pack for quick shift.

Any idea?

Thanks.

Duncan Watts in England builds 727s and they live behind 700hp hemis. Cost (if you provide the trans) is about £1000 though.

Which part broke?

Personally I would build the trans myself. It is not hard.

You could also try using one of these transmissions as they bolt straight up to Mopar Big Blocks.

http://uk.youtube.com/watch?v=rLDgQg6bq7o

Sorry. Wrong one. THIS is the Chrysler version.
http://uk.youtube.com/watch?v=pbVY5teBz ... re=related

The broken part is the overrrunning clutch. The spings are totally destroyed and the rollers are squared.
Do you know the reason to break this?
The rest of parts are ok.
The front planet carrier are 4 roller.

Yes. This part is the most likely to break and the most dangerous to break because it can cause the front drum to spin at twice the normal speed and explode. This is how trans explosions happen.

The 727 can actually take a great deal of power as long as this one part does not fail. Usually it is bad practice during the burnout with a stock type valve body that damages this part.

You need to fit a bolt-in version of the sprag and for safety fit a steel or aluminium front drum that will not explode. These two items are vital on a big power drag car.

How you do your burnout safely depends on if you have a manual valve body or not. I can't remember exactly how you are supposed to do the burnout in each case. But getting on and off the throttle in first gear is usually the cause.

However if you use the correct type of valve body it protects the sprag. So perhaps you need to fit a good valve body too?

This thread has more detail.

http://challenger.mpoli.fi/forum/viewto ... 0111#30111

Thanks for this info Dave.
Now I understood the reason. I started the burn outs is first gear, I'm not sure about the way Is working the rear sprag in first gear but Is totally destroyed and the cause is this, sure.
Anyway I can get this part and install it again.

On the other side, I saw the second gear band a little black coloured. What means that? The discs are perfect and it's a four roller planetary style. Both things are important I think.

I try to post pictures.

Thanks again to everybody.

Pictures

More

The second gear band is nearly black

That band looks as if it got burnt a little. If it still has plenty of material on it I would just re-use it and double check its adjustment.

Make sure the spline count and shape is the same for the planetary gear set as the output shaft. They DID change spline count and shape,(angle), in 1976, 1994. So there are 3 different spline counts and angles. 1962, 1976, 1994. If you are using different internal parts such as the 3,4 or 5 pinion planetary gearsets from different years this will cause a mis-match and thus a failure. If all the parts are from the same year disregard.

I will check everything, but I have a friend with 44o engine satellite who wants this transmission. I will repair it and I will look for another one which handle the torque.

Arruzza told me that he met a guy who build custom transmissions with best parts and he recommend him to me.

He use a best new parts and make it with his specs for each engine he build for his customers. Arruzza promised me zero problems with it.

At this time this is enough for me.

Sounds expensive.

What do you think about the sound of two grands?
I deduct 1200 from my repaired trans.
The balance is 800$ plus shipping, installation and oil.

That sounds pretty good when you put it like that.

Hello.
Today just arrived the new transmission, two months later.
Finally it's a Frank Lupo's Pro-formance 727. Full automatic and I will install the deep aluminium pan like the other.

On the other side I want to install a new transmission radiator to keep the oil colder, instead the summit radiator I'm currently running.

I like the B&M with fan included and plate style http://store.summitracing.com/partdetai ... =BMM-70297

What do you think about it?

If you already have an electric fan or water pump it is a bad idea to add another current drain.

If you mount the cooler a half inch in front of your radiator it should not need a fan.

The 727 can take a lot of horsepower and torque with the right (read expensive) parts in it. Our race car,(BA/A NHRA CLASS record holder 6.98 second et.) with the present Steve Schmidt engine dynoed at around 1200HP, uses a highly modified 727. Changes we've made to it.
A: Input shaft..B. Both Drums..C. Intermeditate shaft..D..Out put shaft..E. planetarys and rear support..E. pump modifications..F.Grinner trans-brake..along with heavy duty band strut, trick band lever, heavy duty band anchor and other items the owner experiments with that I may not be aware of.
An interesting side note is the bands and frictions plates in our transmission are not high dollar trick pieces.

The bolt in rear sprag repair kit has been difficult to find lately. To the best of my knowledge all of them from all the current suppliers are just modified stock units, usually out of old transmission cores. We're looking at making new billet ones in the future.

An automatic transmission can be made to take a lot of power and torque. However, like all high performance items, if you want them to live, they ain't cheap.

transman

I wish all the parts used will handle the engine power without problems.
Now I need to learn to do the burn out correctly.
Every driver have his own tricks to do it, but I read several ways.

The rear sprag broke due a bad burn out.