4+3 trans swaps
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Are you sure about that? I would diagnose the electrical circuits first before going to the work and expense of converting.
Most of the 4+3s "fail" due to electrical problems, which are very cheap to fix. Does your dash indicator light ever come on when you hit the overdrive switch (when the car is warmed up and on the highway). ?
Most of the 4+3s "fail" due to electrical problems, which are very cheap to fix. Does your dash indicator light ever come on when you hit the overdrive switch (when the car is warmed up and on the highway). ?
Advanced
Joined: Aug 2007
Posts: 60
Likes: 0
From: Hood River OR
The overdrive indicator seems to work OK. When I bought the car it was spewing trans fluid out of the vent hole, the vent tube fell out and was melted by the exhaust. I replaced the tube (had to pull the trans to do this) thinking everything would be cured, ran the car on jacks and it continued spewing but it did go into overdrive. It stopped spewing when the fluid was down a 1/2 inch or so. When I test drove it the indicator came on and the car only actually went into overdrive when decelerating or coasting...to me it seems like it has a blown seal that allows fluid to bypass the hydraulic clutch and exit the vent.
Additionally there was a lot of metallic sludge in the manual portion, and third gear is noisy, the car has 97000 but I think it's had a hard life
So I'm probably looking at full trans rebuild or replacement. I admit I don't really like the thought of cutting up the tunnel, but it seems you need to do this for all the other swaps too.
Additionally there was a lot of metallic sludge in the manual portion, and third gear is noisy, the car has 97000 but I think it's had a hard life
So I'm probably looking at full trans rebuild or replacement. I admit I don't really like the thought of cutting up the tunnel, but it seems you need to do this for all the other swaps too.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Has the 4-speed fluid level been dropping? Maybe that's getting sucked into the overdrive. This will prematurely wear the 4-speed too and overfill the overdrive.
You really don't want to rebuild it, it's not cost effective at all. Your cheapest option is buying a used 4+3. 2nd cheapest is the ZF6 swap (~$1600), but that will change if this T5 swap pans out.
I have a used 4-speed unit for sale if you end up needing that.
You really don't want to rebuild it, it's not cost effective at all. Your cheapest option is buying a used 4+3. 2nd cheapest is the ZF6 swap (~$1600), but that will change if this T5 swap pans out.
I have a used 4-speed unit for sale if you end up needing that.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
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Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
Why are the holes for the CBeam slotted? I'd think that would tend to make the drivetrain more likely to flex or misalign. Are they just slotted until they figure out the final placement, or is that it?
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
What I will probably do just to be safe, is run two 1/2" spacer stock in there, which once I get the bolts semi-torqued I'll weld in place then final torque. But I don't think thats required, just a "might as well"..
-- Joe
Last edited by anesthes; Nov 22, 2007 at 10:20 PM.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Everything fits fine with the bracket. Tranny is in. I'll probably get around to doing the shifter mods this weekend, after I bleed the brakes on my plow truck.
Might as well order your adapters, guys who need them.
-- Joe
Might as well order your adapters, guys who need them.
-- Joe
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
After doing some measuring, I found that the shifter stick needs to go
about 3" to the left, and about 2.5" back. As you can see in this picture, the shifter mounting boss is not only centered, but way farther forward than the ZF or the 4+3 shifter would be.
This can be solved with some 3/8x1" bar stock. Cut the base of the shifter off right below the holes, weld a 2.75" long peice to it, then weld
a 1.5" long peice to the end of that, then weld the peice of the base you cut off to it.
-- Joe
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
This is going to result in the shifter rising towards 5th gear and sinking towards 2nd gear. I suggest you leave the shifter sufficiently long so this effect isn't as noticeable.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
-- Joe
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Heel & Toe
Joined: Nov 2007
Posts: 18
Likes: 0
From: kannapolis nc
I am interested in doing this swap are all the input and output splines the same. is cutting the driveshaft down the only other thing i have to do beside fab up a shifter, and buying the adapter . thanks.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
http://members.cisdi.com/~anesthes/f-car-t5/
Splines are same. Use a D44 driveshaft if you have a D36 rear. Cut and modify the shifter. Buy the bracket. Bolt and go.
-- Joe
Heel & Toe
Joined: Nov 2007
Posts: 18
Likes: 0
From: kannapolis nc
ya i already have the d44 rear because mine was a 4+3 right? i also have talked to tom of prostreet and plan on buying the cbeam adapter in the next few days. ill just have to get my driveshaft cut down a inch or so right. thanks
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
I keep forgetting about '84.. The D44 came out in '85.. You just need a D44 driveshaft. call vette2vette.
After that and once you heve the cbeam adapter, just find either an S10 or a mustang hurst shifter, and do some cut and weld. I'll post some pix of my modified shifter soon.
-- Joe
Last edited by anesthes; Nov 30, 2007 at 12:59 PM. Reason: oops.. 1984