Low/Reverse Band and manual VB?

Can someone please expand on the quote below. I dug this out of an old thread from about 2003 sometime.


"If you have a lot of torque its safer to go with a full manual valve body. Reason being, the low/rev band is always applied in 1st gear to avoid killing the sprag and or breaking the low/rev drum."

Jay www.broaderperformance.com



What happens with the low reverse band and sprag in normal valve body operation and how is it different with a manual valve body?

Actually as far as manual VB's go only a forward patter full manual would use the low-reverse band in 1st gear. Most reverse pattern full manuals only use the 1-way clutch for low gear.
A stock C-4 with unaltered VB would not apply the band in 1st gear when the selector is in Drive position. In 1st gear position the band is applied to give engine braking.

So does a full manual shift kit (say the transgo 40-3) achieve this or only a purpose built manualised valve body[img]/phpBB/images/smiles/icon_confused.gif[/img]

I really need to stop reading about this stuff and get out into the shed and pull my box out of the car.[img]/phpBB/images/smiles/icon_spin.gif[/img]

The TRansgo ket make a forward pattern full manual and the low gear band is used in 1st gear.
It is agood working kit though, my brother used one in his 10.0 Falcon

Mario, could you give us a run-down of reverse vs forward valve bodied trans' function? Reading your earlier post it looks like a reverse VB does not provide engine braking in low gear?


[addsig]

C-4 Valve body 101 (to my best knowledge I was wrong once before[img]/phpBB/images/smiles/icon_lol.gif[/img][img]/phpBB/images/smiles/icon_lol.gif[/img]).
Stock VB
D pos - 1st gear - Forward clutch & 1 way clutch
D pos - 2nd gear - forward clutch & intemediate band
D pos - High gear - Forward clutch & direct clutch
1 pos - Forward clutch & low reverse band
2 pos - forward clutch & intemediate band
Rev pos - Direct clutch and low reverse band

Manual forward pattern
D pos - High gear - Forward clutch and direct clutch
1 pos - Forward clutch & low reverse band
2 pos - Forward clutch & int band
rev pos - Direct clutch & low reverse band

Manual reverse pattern
D pos - High gear - Forward clutch and direct clutch
1 pos - Forward clutch & 1 way clutch
2 pos - Forward clutch & int band
rev pos - Direct clutch & low reverse band

Manual reverse pattern with tranny brake
D pos - High gear - Forward clutch and direct clutch
(if brake is applied nothing happens)
1 pos - Forward clutch & low reverse band
(when brake is applied the direct clutch is applied locking tranny up)
2 pos - Forward clutch & int band
(if brake is applied tranny goes to high gear - direct clutch is applied and int band is disengaged)
rev pos - Direct clutch & low reverse band
(if brake is applied nothing happens - I do not think, will have to prove that)
[img]/phpBB/images/smiles/icon_confused.gif[/img][img]/phpBB/images/smiles/icon_confused.gif[/img]

Now this list is from my experience with various VB's I have seen or heard about.
Performance Automatic has a new brake with an external solenoid that may work quite different but I doubt it.
ATI states in their catalog that a reverse manual is quicker then a forward manual because the low-rev band does not have to disengage to make the 1-2 shift.

Hope this helps someone.

Thanks Mario, looks like the only "change" is in the manual reverse VB. I have seen it mentioned afew times on the forum and was just wondering if there were any other changes.


[addsig]

Oh this is great... i learn so much here.
Thanks Mario

Thanks for the replies guys. Just printed that thread out to add to my pile. Can't wait to get one of these boxes apart.