I just picked up my TH400 from the tranny shop today. They installed a new vacuum modulator that looks nothing at all like an original. I mentioned this to the guy that did the rebuild and he said that's how all the new ones are.

I didn't have an original on it when I got the car. Anyone have a source for one that looks more original?

They probably installed one of the new small size adjustable units....they work ok, but are not correct. You want the large size OEM unit...I believe they are blue or black...may be able to provide photo if you need it.

wilma

Tranny shop did the same to me, but I had my old modulator. Problem was, when I installed it, the trans wouldn't shift right.:sad: You might ask your builder if the old style modulator will work on your trans.
If no one else posts a pic, I'll try to get one for you tomorrow.
BillL

Thanks fellas. I remember what the old ones look like from my previous SS, just wondering where to get one.

Summit has them for $109.00

http://static.summitracing.com/global/images/prod/norm/acf-8662967_w_m.jpg (http://store.summitracing.com/largeimage.asp?part=ACF-8662967&Prod=&img=acf-8662967_w.jpg)

Original GM unit has this part number #8623365....also has 6312 and a "B"....there is a threaded adjustment screw which is factory sealed with a some kind of glue. My understanding is this sealant can be heated/melted slightly to allow the adjusting screw to be turned in or out. Just be careful not to overheat the part...I have a couple of photos, but they are all super hi-res and won't reduce for posting. The Summit part is not an exact replica of the GM part

wilma

Original GM unit has this part number #8623365....The Summit part is not an exact replica of the GM part

wilma

I'm going to be checking my local Chevy dealer as well.

Dan,I have a nice original unit from a TH400 that was in a 70 SS..pm me if you are interested.