love to drive

So far it was worth the aggrivation. Chirps the 255s in second, and third is nice and crisp. It took me a little over 2 hours with a friend. If anyone wants any pointers...ask me while it's still fresh in my mind :)

Ted

ZD75blue

glad to hear it... i'll be installing a shift improver kit soon... i have to work back to the trans, i'm still working on the engine compartment yah know :jester

GTR1999

What kit did you use and what setting? I have the B&M transkit but didn't get to install it yet.
Gary

love to drive

I used the B&M Shift Improver Kit with the street/strip setting.

jerryp58

Glad to hear it worked and you like the results. Kind of wish I had gone with the street/strip too, but it sounded like that might be too radical (I was warned that tires might break loose on hard shift on on-ramps & such -- be careful). 2 hours :eek: Man I work slow :nonod:

Did you put in an adjustable vacuum modulator while you were down there? That made a very nice difference too.

For anyone interested in B&M directions, here they are http://users.erols.com/jerryp58/corvette/bnmkit.htm

VTHokie77Vette

Good to hear it went well. I'm thinking about putting the same kit on my '77 over Christmas break if I can get enough money from selling my books back at the end of the semester.

love to drive

What does the adjustable vacuum modulator do?

ZD75blue

you can adjust the shift rpm with a modulator, so you can shift near redline without doing it by hand...

ZD

love to drive

Ahhhh...how much are they? Are they hard to install? This would be great for the L-48 which doesn't have much past 4000 RPM I'd like to get it to shift ~4500

jerryp58

The vacuum modulator is on the passenger side sort-of-front of the transmission (at least that's where it is on mine).

I bought mine for about $12 at Advance Auto.

It looks just like the non-adjustable, but it has an screw in one end that lets you change the shift point. If I remember correctly, the further in you turn the screw, the higher the shift point. I turned mine in about 3 full turns from the setting out of the box and under moderate acceleration, I shift at about 4k.

It just slides into the trans (I think my instructions said to coat that end with trans fluid or grease) and then connects to a rubber hose, that connects to a hard line, that goes up to the back of the intake manifold, and connects to a vacuum fitting by another short rubber section. Check that upper rubber section; mine was badly cracked (not sure how that may have affected trans performance).

There's one bolt that holds a retaining plate which holds the modulator in place. Mine was a little difficult to turn the wrench on, but it is a fairly easy job. It took me about 30 minutes all together so it should take you about 6 minutes (based on your 2 hour shift kit install versus my 10 hour!).

I hope this helps. If you put one in, I'll be really interested in hearing what you think of it.

Jerry

love to drive

Jerry,

Thanks for the info on the vacuum modulator...sounds like something I will benefit from. I'll pick one up sometime and slap it on this weekend. I'll let you know what I think of it.

Ted

98RKC

I've been thinking about doing this myself. I had one in my camaro back in the 80's with no problems but for some reason (probably my age and concern about a dollar) I'm worried that a 20 year old transmission with 75,000 miles on it might not be able to handle the pounding a shift kit would give.:smash:
Am I way off base here and have nothing to worry about? To the best of my knowledge the tranny is in great shape, I have no reason to believe otherwise.
Opinions..... :yesnod:

jerryp58

Acording to what I read in a book about transmissions & the TH350 in particular, a shift kit will do nothing but GOOD for the life of your transmission if it is already in good health. The slushy shifting built into automatic transmissions is strictly for the comfort of the vehicle's occupants. The slippage causes excess heat for the transmission and that's always bad. A quick shifting transmission will be cooler & last longer (at least according to what I read). BTW, I think I'm also going to try some of that transmission additive designed to let the trans run cooler.

I understand your reservations though. That's why I had such a tough time touching mine (probably 150k+ miles). I've had little success with transmissions in the past & I got to the point where I didn't even like changing the fluid & filter. Mine has been going great with the shift kit since April now (wood :smash: ) and I would have to say that from what I saw in the pan, it was not trouble-free at that time. Hopefully, it'll last a good while longer, but the book did say that a shift kit will not do anything to help an ailing transmission and depending on the problem, might actually hurt.

I would think that the only thing that would be under extra "pounding" would be the u-joints & such. But, unless you're pushing some serious horspower, I would think the rest of the drivetrain would hold up fine.

Not an expert by any means here, just my $0.02

Jerry