from reading some posts on the forum, i'm thinking of adding a shift kit to my th350. what exactly does it do and what differences can i tell with it installed versus what it is now?

 

+1 I've been kind of curious about whether or not the upgrade would be worth it. I'm somewhat familiar with how the shift kit works and what it will improve, but is the difference notable?

 

The difference is very noticable. It will change the shift points as well as the delay on the shift, meaning it will engauge the gears more aggresively.

 

how much will it change my 0-60 time?

 

Dunno, it will get it down a bit but I have no idea how much. I recon it would depend some on what they are now

 

Generally a shift kit will firm up the 1-2 and 2-3 shifts by changing the line pressure in the valvebody. All but one check ***** are removed and the restrictor plate that comes in the kit will have a slightly different pattern of holes in it, one of which is bigger and the instructions tell you to make sure it is drilled to a certain size. They even give you the correct size bit in the kit. All of the B&M shift kits I've gotten already has this mod to the plate and it is a direct bolt on procedure. The reason for the use of a shift kit is to take away the overlapping of gears and clutch pack slippage that occurs during shifting. This causes extra heat ie: more wear on the clutch packs. Before installing a shift kit on any transmission be sure to evaluate the current condition of the rest of the trans, like how many miles are on it since the last rebuild. On a TH350 there are 3 sets of clutch packs plus one set of clutches at the front of the trans. I would replace all of those clutches before installing a shift kit because you can run the chance of shattering any thinly worn clutch fiber plates during this hard shifting. The shift kit alone isn't that hard to do if you can remove the trans and do it on a bench with it upside down, but on the car can be difficult due to the fact that gravity will make it difficult to keep things in place as you re-assemble (especially the checkball, but you can use a dab of grease to hold it in place). Also being upside down under the car you better make sure you put the checkball in the right place after looking at the instructions and climbing back under the car. Due to the clutch pack reason I mentioned before it's probably better if you let a pro trans guy do it at a reputable shop. I did mine myself but I had practice on a couple of previous trans's that broke and had nothing to lose when I took it apart to see what broke. This was not on my vette at the time. I have been told that I was lucky to put these trans's back together without a jig to hold it upright while I installed all the planetary gears and clutch packs on my bench, but I got the job done and my vette trans operates great. Although I did install a manual valvebody on mine and the procedure wasn't that different to just freshen up the trans. Mine still had good tolerances inside on the case saver and I took the time to install ALL new bronze bushings everywhere, including new seals on the pump. The seals on the pump can be tricky to compress while sliding the pump back into place without a ring compressor type tool and actually I broke one of the ring seals and the pump shaft trying to re-install it into the case. So I broke down and had a pro do it for me but other than that I did everything else right and it turned out good.
NOW, you can take a chance on your old parts like I did on my 78 Chevy sport van and be alright but the shift kit will find any weak points in the trans. After like 2 years on the van I stripped out a primary input shaft in it's drum due to the hard shifts and heavy weight of a van, but the clutches were good when I did the install.
The shift points generally won't change unless you have the governor modded but it will take it to a few rpm higher to shift because the line pressure is different now. It will also vary if you have a diff stall speed converter than stock. I hope this helps in your decision to do the mod yourself or have a pro handle it and if you decide to ensure the rest of the trans is up to the task of chirping the tires at every hard shift.
I think I have pics of the inside of the van trans when I did the repair, I'll have to look if anyone is interested. Good luck.

 

I put a B&M kit in my Vette back around '78 and I've been barking my tires on the 1-2 shift ever since...................

 

I haven't expeirenced a shift kit in a TH350, but I have succesfully installed a shift kit and hardened seperator plate in my 4L60E( 2000 Silverado 1500). All in all the installation was fairly straight forward and easy-just very time consuming and dirty. The results are a much improved 1-2 shift (chirp the tires), and a firm 2-3 shift. My expeirences with it in my transmission is that is doesn't increase line pressure-just changes volume and rates that the fluid flows. It doesn't allow the clutches to slip as much-so the clutches wont wear as fast.

Hope this helps out.

 

I put a Transgo in my TH350. Kit came with a step by step (and I mean step by step) video to help you through the install. Very straight forward...but there are some moving parts to mess with.

 

I had a professional install a transgo in my 78 a few years ago. The only differences I have noticed the most are the shift points changed into higher rpm zones and I can down shift like a manual now.

 

I've used the Trans-Go shift kit in TH350's, 400's, 2004R's and 700R4's. Everyone was striaght forward, no surprises. And worked really well.

Without exception, the shifts were all better (firmer) and were very dirveable. Jump on the gas and they'd make the tires bark on the 1-2 shift.

As far as rebuilding goes, I've done them in a 30 gallon barrel, on the ground, on the bench with the holding fixture and had good luck with them all.

I'd be a bit leary of installing a shift kit in a high mileage tranny. YYOu could rip the clutch facing right off the plate if it was worn or just really tired.

 

I would say 50K miles on mostly city and I would install new clutches. But that is only what I would do.

 

Had a TH350 with a worked 350 in a 70 Chevelle, had a local speed shop install a shift kit. Wanted them to "lock it out", so it would only shift manually, but they refused, saying they wouldn't do it to a street car. They also installed a new stall speed converter, it was 3000 or 3500 I think, been a long time. I think they also replaced the valve body, once again, been a long time; used all B&M parts.
That car was a blast to drive after the work was done. When driving it hard and either shifting or letting it shift, it would really slam into gear. If someone had a beer between their legs, most of it wound up on their pants.
Have pretty much always owned manual transmissions, but if I get another auto it will have a kit installed.

 

I wondered how to do that as well when building mine, but got a full manual foward shift valvebody instead. The mods are designed into it already plus a few other things about it make it different.

 

I just finished installing a TRANSGO kit in my Art Carr 700r4. Before it wouldn't hold manual low, it would short shift the 1-2 @4000rpm at WOT. Under normal driving the 1-2 would happen at 2200 and the 2-3 would follow immediately at 2400 (stacked shift). Pressure was good.

Now it holds manual low, shifts1-2 @3500 and 2-3 at 4000. Those shift points are a little high but I can adjust that. Shifts are firm but don't bang. I think I made a good decision. My trans guy wanted to rebuild it for $2000+. The shift kit was $140 and my labor (and my son's) was free!

 

I am tell you all what, there is NO OTHER SHIFT KIT but TRANS GO, all the rest suck.....

been my experiences for some 40 years now.....

and countless miles on more than a few of his kitted up trannies....

 

 

i would like to thank everyone for all the input. i will go ahead and have my mechanic install the kit for me as he can probably use his lift nad it would be much easier anyway.

 

so i finally installed my shift kit...

 

Trans Go