I am considering rebuilding my tranny this winter, What is involved and any "real" special tools needed? It was redone MANY years ago with a full B&M kit but is now slipping slightly from second to third. First to second still loosens you fillings! And it had developed a few small leaks.. Ideas? Kit to purchase? Scotty P
Is not a hard job to do but I would advise getting the Haynes trans book to use as referance. The only real special tool needed is a pair of snap ring pliers and a dial indicator, also either a press or something to compress the high clutch piston for seal replacement. Many sources for rebuild kits online or local supply stores. Just get the basic kit with steel clutch discs included. Cleaning and inspecting is the worst part of the job, making sure all bushings are in good shape and no cracks or worn parts such as thrust washers and associated bands and drums etc. All this is explained in the manual. Critical points are the clutch pack clearances and also the total end play of the assy. measured at the input shaft. Would suggest you pick up another trans at a salvage yard for referance and or parts and practice etc. Try and find a "H" or "R" servo to help that pesky 2 to 3 shift flare. Once you have done one of these, you can do most any trans of early design.
Good advice Old Guy!! I was amazed at how simple they are to rebuild when I first took mine apart!! Now I think i'd rather rebuild a tranny then I would a motor!!
Dave; where would you find one of the servos you mentioned? Do you have a part# that I could reference? Trans are not my thing, but is the servo difficult to replace? Thanks,
Earl, I find mine at local salvage or scrap yards. It is like a treasure hunt to find one, usually can get them for around scrap alumnum price or better yet I just buy the whole tranny for 15 to 25 bucks. Sometimes are listed on ebay but can go for around 25.00 or more. The R is a bit more popular because of it's larger piston etc. Most c4's come with a "teenie" A or B servo, which works well but for lead foots like me, would rather have the neck jerking shifts and even longer life out of the slush boxes. PA Automatics makes a billet aluminum one of there own for around 100 dollars or so. Not real hard to change them, tighten up the band adjuster real tight and then carefully remove the servo so as not to lose the strut that is on the end of the servo piston rod and in the band slot. This is a bit tricky and messy along with the spring that is going to push outward on removal. Best bet is to drop the tranny pan and then you can see the strut and with a helper, can remove and install the H or R one a bit easier. Be sure and put new seals on the piston and cover, along with a new gasket. The larger internal diameter of them, allows for a bit quicker band clamping and also more important to me is the quicker release. As with any mod's to the c4, how well it works will also depend on the condition of the "whole" transmission in general. Just another small deal can really help too, by doing a slight modifcation to the servo and plugging the hole in the case, but this really raises pressures to a point of breaking the stock H and R covers. Really not necessary on normal driven cars, so just try to get one and install it as is. In the case of these servo's, bigger is better.
dave, is there a marking on the servo itself that will let you know that you have the "r" servo? what years would we find these on? thanks for the mod. suggestion. earl...if you go looking, find "two". i will do the same...frank...
On the cover for the servo it is marked... The servo's have a round circle divided into 1/3rds... It's usually on the bottom third. Kinda hard to explain, but they are marked on the outside on the case. I'll try to go take a pic of a C6 or a C4 one i have laying around in the shop sometime today.
Not for sure on this, but I think they came in 351W trucks and vans in the mid 70's and up. So many tranny's have been changed out over the years in different models, it is hard to guess what is in what anymore. Just have to look at each case and servo for ID. Wish I lived close by and could help you more on this, in person.
