Can anyone recommend a Reverse pattern valve body for a 904 with low band apply? This will be a track car basically. Any info you want to share is appreciated aswell.
AL...

Griner Engineering model # 12/22G05B

Griner's website is currently under construction, www.griner-racing.com

However, moparts member 727Jim (Jim Santo) is a Griner dealer, and can get one if Griner is out of stock.

RJTRANSMISSIONS@AOL.COM

John

a&a makes one as well...dont see how you can go wrong either way...i have a griner low apply tbrake valve body for my 727..cant wait to use it.......the a&a is available for footbrake as well as tbrake,and for 727/904.....

So far this year , I have installed/sold over 50 A&A reverse manual valve bodys with out a single problem. A&A was the leader in low band apply technology.

From what I have seen, both the A&A and Griner units are good. I bet Trans Act, and Pro Trans likely have one with low band apply too.

Last time I talked to him, 727Jim had the Griner valve bodies in stock and ready to ship.

What is a low band apply valve body?What are the advantages?I have a cheetah....thanks,Bob

There has been a lot of talk about aftermarket manual valve bodys with the low band applyfeature,and for good reason. First, you should understand how the low/reverse band in Chrysler transmission works. In a stock 904 or 727, the low/reverse band is applied when the gear selector is in R / reverse and/or L / first gear, sometimes called low one.When the gear selector is in the D position and the transmisssion is in first gear, the low/reverse band is NOT applied. So, the low/reverse band does not have to be on to get first gear. When the low/reverse band is on or applied, the band is applied around the low/reverse drum. The low/reverse drum is splined to the overrunning clutch, also called the sprage.

727 low/reverse drum,low/reverse band,sprage race

When a 727 or 904 transmission is in first gear, D, or L the sprage is in the locked position. ( note: the sprage free wheels in 2nd & 3rd gear) Having the low/reverse band on will keep the sprage in the locked position under heavy or high performance loads. Now, the sprage AND the low/reverse band are working together to keep the low/reverse drum in the locked or stopped position. You can try this in your rear wheel drive mopar or your Dodge ram. Test drive the car or truck with the gear selector in D. Note the feel of the 1-2 shift, then put the gear selector in L, shift to 2, and you will feel the bands overlap. The shift will not be as quick and or firm. (note: the KD band comes on / is applied in second gear) This is the problem that aftermarket valve bodys had when making the 1-2 shift in racing transmissions. As we all know, when racing we want quick/firm shifts, if not, we would have probs with burning up bands because band over lap is having both bands on at the same time, or the timing of the bands coming on then off to make a clean and firm 1-2 shift. So what was the only solution (at the time) to make the 727 & 904 have a clean and firm 1-2 shift? Leave the low/reverse band off/unapplied in first gear. Remember, the low/reverse band does not have to be on/applied in first gear, to get first gear.
Now, by leaving the low/reverse band off, the sprage has to do all the holding of the low/reverse drum. This now makes the sprage a weak point in the 727 trans because the low/reverse band is not applied along with the sprage.

What happens to a 727 when the sprage fails? The transmission will free-wheel at 2x the eng. RPM. When this happens, and the stock steel front drum is in the transmission, the front drum will explode.


This 727 was in a 11 second bracket car,that did NOT have low band apply.
How fast are you going ?

Now that you know what can happen when having the low/reverse band off/unapplyed when running a stock steel front drum, it's like having a time bomb strapped to your car. Do you want a valve body with low band apply? I know I do.

How can the 727 sprage fail in a racing transmission ?

1. Any time the sprage is shocked, you break a U-joint, axle, or ring&pinon, it can cause sprages to fail
2. Driver error. In the heat of competition/excitement a driver could accidently nuetral-drop the transmission. I know what your thinking, I've never done that. But it could happen.
3. If the carb or ignition causes a back-fire and the car noses down and picks back up, or if you get in and out of the throttle while in first gear, you can damage the sprage.
4. If the car hooks, then the tires spin, then hooks again, the sprage can fail. And I know none of us have EVER had traction probs. (yeah, right)
5. Doing burn outs, starting in first gear is the biggest no-no of all. Burn outs should be done starting in 2nd gear and shifting into 3rd gear.
All 5 conditions are while in first gear.

How can you tell if your manual valve body does or does not have low band apply in first gear?
With the transmission in first gear and driving about 20 MPH , let out of the throttle, if the car goes to idle and the motor does not help the car slow down, (engine braking) you do NOT have low band apply in first gear. If you car slows down and the motor helps slow the car down, you DO have low band apply in first gear. Note: If you know you have a valve body with low band apply in first gear and your car does not have engine braking, your low reverse band may be out of adjustment or you may have a broken band strut, or you have a cracked low reverse pistion. Checkng to see if your low band apply is working ,you can test this by checking the engine braking in first gear.

When installing a reverse manual valve body, or a trans-brake valve body with low band apply, it is recommended that you also install a billet low reverse servo kit.

That being said: FWIW, I have a Tranz-Act Pro-Brake and it does not have engine braking in first gear.

Great info CRT. So what has been done to the valve bodies w/low band aplied to allow them to shift quicker and harder?
How do they get rid of the overlap?

That is correct. The low/rev band is only on when you have the trans-brake activated. So as you let the trans-brake button off , the band is off. The low/rev band is apply through the trans-brake button. Trans-brakes with low band apply , have the low/rev band on any time your in first gear and not just when the trans-brake is on.

I have a cheeta can you change it over to be a low band apply. If so can you tell me how?

Thank you CRT for the great INFO.

Thanks for the great info John, you really covered evrything quite well. I will keep you in mind when I have to import any of my Transmission parts that I cannot source over here. Thanks again,
AL...

I too have a older cheetah and was wondering if it could be converted or are you stuck with replacement. Great info. Are 2 Lancers allowed on the same post

TA does not offer a valve body with low band apply. So having the VB updated is not a possibility at this time.

John, the T/A trans brakes have had low apply on a bleed for several years now. This is from the T/A information page.
"As Turbo Action advanced into the 1990's, Turbo Action released the long waited CHEETAH Pro Series Brake for Torqueflite. This brake for the Mopar racers offers quick lock up on roll into stage light; instant release for quick reaction time; low horsepower usage for quick ETis; clean releases for reliability; and two major safety circuits. Special safety features include: No brake in reverse. neutral, second or third gear; and automatic low roller clutch protection with timed release low band, allowing a clean 1-2 shift."

Leigh , yes thats true. But it is not a low band apply trans-brake.The low/rev band is only on when the trans-brake is applyed, and when is the trans-brake applyed ? when your sitting at the starting line waiting for the tree to drop, when you release the trans-brake and the car starts to move is when low band apply is needed the most.Valve bodys / trans-brakes with low band apply have the low/rev band on ANY time your in first gear, with or with out the trans-brake applyed.

I guess it would depend on how long the bleed process is. I'll try and call Forte sometime and ask. Don't get me wrong, it's not a very good brake. I don't like having to stage at 1600+ to keep from rolling, but it definately states overrunning clutch protection via the timed bleed in my instructions as well.

ok so say one gets a low band apply RMVB w/o trans break. how should they burn out? still 2 to 3? couldnt you then go from 1st? i want a mvb for my street (AH! the S word! not in the race forum!) car, and i want all the benifits of street car: downshifting, burn outs. with out all that pesky transmission explosion.

I've got a Cheetah reverse Manual VB in the car and bolt-in sprag lying on the shelf, waiting installation.

So, in a transmission with a rev.manual-valvebody without lowband apply, how much of a protection against tranny blow-up is a bolt-in sprag?

ok so say one gets a low band apply RMVB w/o trans break. how should they burn out? still 2 to 3? couldnt you then go from 1st? i want a mvb for my street (AH! the S word! not in the race forum!) car, and i want all the benifits of street car: downshifting, burn outs. with out all that pesky transmission explosion.
When racing, burnouts should start off in 2nd then shift to 3rd.On a steet car , well, we all do burn outs starting off in 1st gear,So I would have to say , shift into 2nd gear as quick as you can. Maybe Jim727 can chime in on this one.

I've got a Cheetah reverse Manual VB in the car and bolt-in sprag lying on the shelf, waiting installation.

So, in a transmission with a rev.manual-valvebody without lowband apply, how much of a protection against tranny blow-up is a bolt-in sprag?
A bolt in sprage keeps the outer sprage race from spinning in the case, It does not protect the springs and rollers.Low band apply VBs do help protect the springs and rollers , as the low band is ON when in first gear,

I have a cheeta RMV in my car and it's been in there 7 or 8 years many miles and two trans'es later and it's still going strong. street and strip. only trans blowups have come from blowing up 8 3/4 suregrips (junk!! with slicks) low 12's 105 mph 3700 lbs and a 440 with a 727. no frist gear burnouts. these can damage the over running clutch if the tires suddenly get traction. the problem is not having enough elements in the over running clutch. street tires on loose pavement shouldn't give you any problem. and I've been up and down shifting with my trans forever. thoes warnings are just to cover the makes butts

ok all lets see is we can solve a few things john from crt i correct in his last reply

#1 low band apply is extra proctection so you dont over speed the trans in the event of sprag failure

#2 on the burn out thing start in second like you would at the track (street racing not recommended)but if you may still second gear
#3 like john said 1st the second asap you put wear and extra load on the trans think about it the sprag and low reverse band are on with the rear clutch then you go to hit 2nd now you dump the low reverse band and try to clamp the kick down band on for 2nd gear which causes a little slip along with wear then grabs

#4 now racing street or strip you always launch in first so now difference street or strip
#5 A bolt in sprage keeps the outer sprage race from spinning in the case, It does not protect the springs and rollers.Low band apply VBs do help protect the springs and rollers , as the low band is ON when in first gear,
along time ago in the dealership we use to call they case savers you bolted in the outter race to save the case this will not help on over speeding the ft drum and sun shell


now for years alot of people have used many different valve body's with out issues but always remember safety first the tech world has come along ways in 20 years some people say i did my trans for 200 to 300 bucks with a 150 dollar converter well that is nice and all but remember the more HP you put out the more $$$$$$ you need to spend behind that mega motor you may have a awsome motor but what is behind it is what gets you to the end of the track

be safe low band appply is an extra safety measure thats all if your happy with what you got run with it but remember times have changed and so did parts bigger better and baddddddder go luck everyone

everyone i hope between all the replys this has helped if more info is needed please continue to post orcall / pm several of us

enjoy you weekend all