4+3 trans seal
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,328
Likes: 14
From: Stafford Connecticut
4+3 trans seal
When did chevy change the seal between the two halves of the 4+3trans, to a better design.I have the early model 86 vette.What did they change the seal material to ?I would like to use dexron VI synthetic in the auto half.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Over the years here, the recommendation for fluid for the OD unit is to stay with the regular Dexron III ATF and not use a synthetic.
Given the cost of OD repair, I don't think I would want to risk going to a fluid that has not been recommended by the knowledgeable 4+3 OD people on the Forum.
Also, most people follow a OD service interval of 12K miles, so it wouldn't be worth the expense of Dexron 6. Just change the fluid and filter around that mileage interval and it will work fine.
Same goes for the 4-speed portion, just use a good GL-5 75W-90 gear oil.
Given the cost of OD repair, I don't think I would want to risk going to a fluid that has not been recommended by the knowledgeable 4+3 OD people on the Forum.
Also, most people follow a OD service interval of 12K miles, so it wouldn't be worth the expense of Dexron 6. Just change the fluid and filter around that mileage interval and it will work fine.
Same goes for the 4-speed portion, just use a good GL-5 75W-90 gear oil.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
84-85 got the 'first' design 4+3, a few very early 86 got that also before the 'second' design appeared...just open the hood and look at your tpi throttlebody for the 'third' cable that only the early 'first design' trans used, 'second design' will only have throttle cable and 'cruise' cable'
