Hey,

Im going to buy a used 700-r4 trany to replace my almost destroyed one, I was wondering if I should get a shift kit for it. I want it to last as long as I possibly can get it to, and I have heard both, that a shift kit is good and bad, so whats the truth?

Thanks,

J.D.

 

Shift kits are made for transmissions working properly before the installation. Sometimes people think a Shift Kit and Rebuild Kit are the same.

Some shift kits solve the problems seen in OEM 700-r4s.

Like on my stock trans I would get a 300 or 400 RPM flare on the shift between 2nd and 3rd. I put a B&M kit in and it was still there. Eventually got another transmission with a Trans Go and the problem was solved.

Some boost up the fluid pressure hopefully keeping the clutches from burning out as easy.

I've owned both the B&M and Trans Go Kits. The B&M is a neck breaking 1st to 2nd shift every single time (due to B&M bypassing some of the transmission normal operating functions). No matter what throttle position I used. If I was over 1/2 throttle it would chirp the tires like crazy too. Sure it was nice for the first few weeks, but it gets old quick. Especially trying to make a turn onto a 4 lane going across traffic and 2nd gears hits and the car goes sideways because the pavement is wet.

Trans Go offers smooth shifts until I get up to moderate to heavy throttle then it firms up. Not to mention the Trans Go is a little more expensive buy too, since it contains more parts (one fact many people over look when comparing prices). I know I did when I bought the B&M kit.

Both kits allow the driver to hold 1st gear as long as they want. The OEM transmission forces an upshift.

One way people can increase the wear on the transmission after a shift kit install is by forcing downshifts manually. It doesn't a hurt transmission if theres proper fluid pressure but downshifting manually at idle or low throttle speeds can starve fluid. Pro-Built informed me this should only be used as an emergency stop situation, else I should heel and toe the brake and the throttle. That way I can blip the throttle slightly with the brake on, making the fluid pressure go up before the forced downshift.

 

Alright, thanks for the info

 

The B&M Shift Improver Kit (note that B&M doesn't make a "Shift Kit" since the term is actually a trademark of TransGo) will increase shift hardness by enlarging the feed holes, blocking the accumulators and jacking up the line pressure.

The TransGo Shift Kit contains a number of parts which repair common design defects in the transmission, but isn't intended to change the shift feel. The TransGo Reprogramming Kit will allow you to adjust shift feel. Unlike the B&M kit though, the TransGo changes the timing of the application and release of individual clutches to reduce wear.

 

You should match the rpm's, when making a manual downshift, before letting off the throttle. It is like "double clutching" a manual transmission. You do not want to downshift an automatic transmission just by moving the lever and nothing else, as this will wear out/glaze the clutches/band very quickly, as the line pressure is very low at closed throttle openings.

 

Yea i was wondering about this too...

I was thinking about getting the B&M kit to extend the life of my transmission. I have the 305TBI so i doubt my car will break loose w/ the 1-2 shift.

I am just wondering that during normal driving conditions (i dont race my car, i actually baby it), will it extend the life of my tranny?

 

The B&M kit is probably more likely to reduce the life of the transmission.

 

Yea after doing some more reading i found out that transgo is the much better (and much more expensive option).

I have 2 questions about it though...
how difficult is it to install?
and would it be ok for my application (regular driving, no racing, just looking to extend the life of my transmission)?

 

It's not necessarily difficult to install, but it's somewhat involved and requires some care and attention to detail.

 

Well my dad was a mechanic for Pontiac, Buick and Chevy during the 80's (he can work on my car blindfolded) and hes built a few chevy 'racecars' in his day...so i'm sure he could do it, however i'm not sure if we have the right tools at our house. How high off the ground does the car need to be because we dont have a lift...