Author Topic: Reverse Manual Valve Body  (Read 3020 times)

Offline c_u_d_a

  • Jr. Member
  • **
  • Posts: 18
Reverse Manual Valve Body
« on: August 25, 2006 - 02:04:33 PM »
Are there any changes, other than perhaps a low/reverse billet piston, that should be made when going from a auto VB to a manual VB?




Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #1 on: August 25, 2006 - 04:32:23 PM »
 Yes, the billet rear servo :thumbsup: and I definitely recommend a "low band apply" manual V.B.
  If you do not go low band apply then have a bolt in sprag installed.
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline c_u_d_a

  • Jr. Member
  • **
  • Posts: 18
Re: Reverse Manual Valve Body
« Reply #2 on: August 25, 2006 - 05:15:31 PM »
Which VB with low band apply do you recommend for a street/strip application? I was considering the Griner VB.

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #3 on: August 25, 2006 - 08:02:59 PM »
Forward pattern  http://jvxracing.com/ 1-800-727-5891 talk to John Vinson, tell him Terry from TAC Transmissions sent ya. :thumbsup:
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #4 on: August 26, 2006 - 08:16:08 PM »
It depends on how much HP is in front of the transmission. You can run a manual VB on the street. If you have a 500 + HP engine in the car I would use a manual VB. If there is a bunch of modified parts on the engine (carbs, intake etc) it is usually too hard for someone to get the throttle pressure linkage working correctly. At that much HP the life of the transmission will be short if the TV linkage is not 100 percent correct.
Manual VB's also have a stiiffer pressure regulator spring putting more squeeze on the clutches and bands.
If a car is going to see the track 2 times out of the year then that is a different story also, but most people that build high HP engines like to run 'em!
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: Reverse Manual Valve Body
« Reply #5 on: August 29, 2006 - 06:41:26 AM »
Griner is also a good one. One of the better ones IMO. In terms of making a trans bulletproof, there is only one part that HAS to be changed. That's the front clutch retainer. Spragues will still defrom and break, even when bolts are used. All the bolts do is stop the outer race of the sprague from rotating in the case. This will still allow the clutch retainer to freewheel and explode. The upside, billet steel and billet aluminum are available. The downside, trying to convince someone his foot is worth $500, and the bolt in sprague wont fix it...lol. (a low band apply VB will go a long way to stopping the issue too, but in very slim chances, it can happen until the drum is replaced)

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #6 on: August 29, 2006 - 07:13:34 AM »
The reason I advise a bolt in sprag with a "no low band apply " VB is to try to do everything I can to save someone's foot!   
Spragues will still defrom and break, even when bolts are used. All the bolts do is stop the outer race of the sprague from rotating in the case. This will still allow the clutch retainer to freewheel and explode. The upside, billet steel and billet aluminum are available. The downside, trying to convince someone his foot is worth $500, and the bolt in sprague wont fix it...lol. (a low band apply VB will go a long way to stopping the issue too, but in very slim chances, it can happen until the drum is replaced)
:grinyes: 9 times out of 10 it is the rollers that fail in the sprag,it is very hard to get someone to go to a low band apply VB when they have not used one for 15 to 20 years with no failures. :dunno:
If you use a low band apply VB your chances of a a direct drum failure are almost zero !
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline c_u_d_a

  • Jr. Member
  • **
  • Posts: 18
Re: Reverse Manual Valve Body
« Reply #7 on: August 29, 2006 - 05:35:11 PM »
Does a bolt in sprag really offer much improvement? It seems to me given the clearance between the bolt and the bolt hole that the outer race will have already started to turn in the case before the bolts offer much resistance.

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #8 on: August 29, 2006 - 08:18:21 PM »
The thing that makes the biggest improvement is a low band apply VB!!!!!!!
(I do not like no low band apply VB's) :burnout:
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: Reverse Manual Valve Body
« Reply #9 on: August 30, 2006 - 06:44:23 AM »
Like tactrans said. the best way to limit the "worst case" is to run a valve body with low band apply. I havent seen the rollers fail, but I have inspected several where the thin steel tangs had begun to deform the wrong way, and I've found plenty of broken springs. The botl in spragues for the most part will only limit the rotation in the case. When it's all tight, there is the very slim possibility of the race moving a little. But it would take a lot of abuse before it moved. The tangs will disfigure long before the race moves with bolts.  I describe the whole thing like this.. You can take a live grenade, and toss it around(no LBA valve body). You can put a wire around the pin and toss it around (LBA valve body and sprague). And you can pick up a dummy grenade, and do whatever you want with it and never have to worry again. The options cost about this: 1. $140 for typical Cheeta VB, less for shift kits. 2.$400-600 for typical Grinner, servo package, and sprague. 3.$1000+ for clutch retainer, good VB, sprague, and servos. What's your foot worth? Or perhaps more importantly, how much to fix (patch holes) the floor and body work should it let go? If it's more tha $1K for either of these, you should buy the better stuff.  Just in case I get the "you must be made of money" deal. My car has had the Turbo Action Cheeta RMVB, factory sprague, servos, original pump, and stock rebuild. I've street driven it for 2 years early in life, and it's raced every summer since at least a few tmies, and runs high 11s. No issues. But, I built it before I knew a lot of what I know now, and I know how things get broken. A lot of guys dont, and that is what hurts parts and people.

Offline tactransman

  • Sr. Resident
  • ******
  • Posts: 5401
  • 1973 Challenger- Member here since April 14, 2006
Re: Reverse Manual Valve Body
« Reply #10 on: August 30, 2006 - 06:54:37 AM »
c_u_d_a tell us your set up (HP,engine size/specs , rearend gears etc.)
Terry-tactransman 
Torqueflite/Automatic Transmission Specialist
Union, Mo.
Give a man a fish and he eats for a day,teach him to fish and he eats for a lifetime.

Offline c_u_d_a

  • Jr. Member
  • **
  • Posts: 18
Re: Reverse Manual Valve Body
« Reply #11 on: August 30, 2006 - 11:45:17 AM »
c_u_d_a tell us your set up (HP,engine size/specs , rearend gears etc.)
I'm building a 572 hemi, 10:1 CR, stage V heads and a solid cam 247@0.050" cam. It's going in a 1974 cuda with 3.54 gears. At this time, I'm limited to P275 rear tire.

Offline moper

  • Resident
  • *****
  • Posts: 2368
Re: Reverse Manual Valve Body
« Reply #12 on: August 31, 2006 - 09:39:38 AM »
Problems arise when one spins the tires, then lets off and get's back on the throttle. WIth those tires, you NEED low band apply, I'd buy the super sprag, and a billet clutch retainer. As a street car, a blanket isnt really feasable, and with that much power on tap, you'll be spinning well into high gear. good luck...lol