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Shift Kit in the C4? Good Idea or Not?

Mikey

Bronco Guru
Joined
Aug 15, 2001
Messages
1,477
Looks like I'm going to have to dig into the valve body on my C4. I put in a shift kit in my 68 Cougar's C4. You guys recommend the same for the Bronco? 3.50 gears, 31 tires, 302 with Holley 4V.
 

bknbronco

Bronco Guru
Joined
Jan 17, 2011
Messages
4,378
Loc.
North Metro, MN
I have done the shift kits on a blazer with 35" tires and it blew 3 trannies in 2 weeks and the last trannie I put back in it I sold it to some sucker. I wouldn't even drive it to the end of the block cause I knew it would explode another trannie. I also had a kit put in my diesel excursion (with 35's) by a big name trannie company. I hated it....it shifted way to hard! I drove that one for 100 thousand miles and hated every mile of it. To me kits and big tires and tar don't go well together. Sure with some tiny tires like your cougar has it will just chirp the tires, but on something with 35's it just chirps the trannie to death! Not a fan of shift kits. Learned my leasson twice over.
 

Mountain Ram

Contributor
Recovering Masshole
Joined
May 8, 2011
Messages
3,387
Loc.
Abingdon, VA
Running a B&M kit in a C4 with 4.56 gears and 37" tires... No problems here. Shift kit has been in the truck since before I bought it with no issues.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,348
I recommend it, some people hate them. A good one will make the shifts quicker (not necessarily harsher) which prevents slippage and makes the clutches last longer. Stock valve bodies were designed to provide smooth shifts by stretching them out and allowing the clutches to slowly apply.
 

bad 68

Full Member
Joined
Jul 1, 2010
Messages
930
Loc.
Northest Washington
There are usually 3 stages of shift kits availible with any manufacturer. If you go with a mild kit it does speed up the time it takes for the clutch packs to reach full fluid pressure and stop slipping. A mild kit should actually extend the live of a transmission.
 

cs_88

Bronco Guru
Joined
Jul 28, 2005
Messages
1,321
I'm running the Transgo 40-2 kit in my C4 and love it.
At light throttle the shifts are nice and easy, when you get in the gas they are good and firm.
I would definitely recommend it.
 

red hot71

Full Member
Joined
Nov 26, 2009
Messages
648
Loc.
kent wash.
I'm with BKN hear my tranny builder doesn't recommend shift kits in large lifted trucks, because with large tires and such it puts way to much strain on all the other parts U-joints, rear end, Tcases. But I think any good tranny builder has tricks up his sleeve that helps anyway as my guy does.

I will say this a lite car, big engine, strong rearend and a turbo 400 with a shift kit sure is fun. Oh and I will add this being 18 or 19 doesn't hurt either.
 

Crude dude

New Member
Joined
Feb 4, 2012
Messages
136
C4 with a shift kit here also. I did the B&M kit in mine and it shift ridiculous hard. Ive been pretty rough on mine and its never had an issue....35" tires with 4.10 gears
 

panteramatt

Sr. Member
Joined
Mar 11, 2011
Messages
654
I have done the shift kits on a blazer with 35" tires and it blew 3 trannies in 2 weeks and the last trannie I put back in it I sold it to some sucker. I wouldn't even drive it to the end of the block cause I knew it would explode another trannie. I also had a kit put in my diesel excursion (with 35's) by a big name trannie company. I hated it....it shifted way to hard! I drove that one for 100 thousand miles and hated every mile of it. To me kits and big tires and tar don't go well together. Sure with some tiny tires like your cougar has it will just chirp the tires, but on something with 35's it just chirps the trannie to death! Not a fan of shift kits. Learned my leasson twice over.

Not quite sure what setup you had but I have a 2000 psd on 37" tires with a john wood VB and wouldnt have it any other way!
 

vintage bronco

Sr. Member
Joined
Feb 8, 2010
Messages
850
I recommend it, some people hate them. A good one will make the shifts quicker (not necessarily harsher) which prevents slippage and makes the clutches last longer. Stock valve bodies were designed to provide smooth shifts by stretching them out and allowing the clutches to slowly apply.

Viper
which one do you use and recommend ?
 

bronconut73

Bronco Guru
Joined
Aug 7, 2012
Messages
9,918
One of the post said shift kits are hard on other parts. Not true. Things like U-joints hate being loaded and unloaded all the time which is what an auto tranny typically does with it's slow shifts loading and unloading the axle radically changing your pinion angle between gears.
Whereas a shift kitted tranny shifts quick not allowing the rear end to unload keeping a consistent pinion angle.

Installed a TCI shift kit in '86. Same tranny, same shift kit, 27 years, but only about 16,000 miles. It shifts perfect, quick/firm under throttle but easy/smooth when just cruising. I believe it was called an RV shift kit.

So from me....a shift kit is highly recommended.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
35,715
Do the mildest shift kit possible and that should be just fine!

Good plan.

Typical factory tuning is soft and gentle. Adding a little shift kit to tighten up the shifts can do wonders for clutch wear and heat buildup. The trick is to go mild and avoid the harsh kits. Most kits have multiple settings. Stay in the lower third of the options. The RV/Tow option is generally good. Avoid any race or competition calibrations.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,348
Viper
which one do you use and recommend ?

Start with a Transgo 40-2. If you follow the kit instructions exactly the shift can sometimes be too firm. I recommend the following. Follow the instructions except use the stock pressure regulator springs, do not install the orange spring under the cutback valve, and drill the holes to only .080-.090".
 
OP
OP
M

Mikey

Bronco Guru
Joined
Aug 15, 2001
Messages
1,477
I'm familiar with the B&M 50262 Shift Improver Shift Kit.....this is what I put in my 68 Cougar years ago.....which is better or does it matter and go for price?
 

NYLES

Bronco Guru
Joined
Aug 13, 2004
Messages
9,846
I'm running the Transgo 40-2 kit in my C4 and love it.
At light throttle the shifts are nice and easy, when you get in the gas they are good and firm.
I would definitely recommend it.

This is whats in mine loved it.....but its ZF week!
 
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