HELP PLEASE with Tremec swap in 1967

"Jason O'Brien" wrote

Read my other post. Windsor Fox has some cool stuff, but they don't back up their stuff like they should. Their EFI swaps are easy, expensive, and aren't the greatest either. Although M&F kisses their ass every moment they can. DB Performance is WAY better when it comes to support and making it work the first time. DB Perf has had to fix MANY a W-F EFI swap.

Thanks again! I will check into that. I have to figure out how to measure that pinion angle. If I have to cut the tunnel (shudder)... what about a T5? Do you have to cut the tunnel with those? I don't know, just curious... wanna keep the Tremec but don't really want to cut the car up...

Thanks!

66 6F HCS wrote:

T5 will bolt in with no probs at all. It's just nearly as strong as the one you already have. If you think a T5 will handle your motor, you could probably sell your tranny and still have some $$ left after buying a T5 since they're cheaper.

"66 6F HCS" wrote

Sorry I meant..."...just *not* nearly as strong..."

No problem, I gotcha...

It's something I will consider, but I did buy the Tremec because it can handle much more torque, hp and doesn't have some of the other problems T5s have been reported to have...

SIGH

Looks like I'll be calling DB Performance, and/or selling the Tremec.

66 6F HCS wrote:

"Jason O'Brien" wrote

I would take the car to a driveline specialist and explain the problem. It may be as simple as the rearend not being tilted correctly to keep the pinion angles at both ends of the driveshaft equal. They would know fairly quickly if there was a pinion angle problem. Lots of people run the Tremec's without cutting their tranny tunnels, but the pinion angles are less than ideal (they are very steep) as long as they are equal you should be OK! You just end up replacing U-joints more often. Get it checked first before doing anything else.

I went ahead and researched it online, then bought a magnetic gravity angle gauge at the hardware store ($10). From what I could tell, the rear end pinion angle is -6 degrees, which may or may not be too steep. I am not sure what the other angle is, because I couldn't get underneath the car that easily, and wasn't sure if it was totally square or not.

Naturally there are differing opinions on the subject. Several sites recommended -5 to -7 for leaf spring suspensions, while others (including Ray Currie) recommended somewhere between -1 to -4 degrees. Here are a few links with illustrations and explanations.

I think I'm going to either bring it to a shop with a drive-on lift, or do what you recommend, which is to take it to someone who specializes in this and have them look at it. Bigfoot 4x4 Inc. is actually located here in St. Louis County. I have taken driveshafts to them for balancing. I think they might know a thing or two about non-stock drivetrains....

Thanks again for your help!

Jason

66 6F HCS wrote:

"Jason O'Brien" wrote

I would stick with Currie's numbers. Those are the ones I've heard from other driveline specialists. I've never heard 5-7 before. 3 is what I've always heard as the ideal angle.

There is no universal ideal angle. The idea is to have the angle go to zero degrees under full acceleration. This provides minimum hp loss and strain on the u-joints. Amount of applied torque to the axles and spring wrap-up will be the primary variables, assuming no tracion loss.

Small engines will need less than big engines. The 5-7º figure would be for a big engine.

All this is assuming no traction device that will limit spring deflection.

"CobraJet" wrote

Thanks for clearing that up CJ. I was going on info I'd heard for years. The less pinion angle the better because of the stress created on the U-joints at severe angles.