98cherrySS

iTrader: (2)

Looks like the Magnum F I just installed will require about 1/2”-3/4” shorter drive shaft. Is this what others have experienced? Would it be reasonable to lengthen my adjustable LCA’s to help gain the space needed?

Che70velle

iTrader: (6)

Same here, but my driveshaft guy took care of this when installing my new front yoke. I think I went 7/8” shorter...1350 yoke is larger, which is reason for needing shorter driveshaft, in case others reading are wondering why this is.
My t56 had no internal stop inside it, so I could slide my driveshaft into my trans until I bottomed against the seal, and then get my rear u-joint to go in. My MagnumF has an internal stop in it, so I can’t slide my driveshaft into the trans nearly as far, adding to this issue. If it weren’t for this internal stop, I think I could have made my driveshaft work without having to cut any more length than the new larger front yoke would have required.

98cherrySS

iTrader: (2)

Yup, you nailed it. I compared the yokes this AM and sure enough, that is the issue. I'll shorten the drive shaft appropriately. Thanks!

gnx7

iTrader: (28)

You could also cut the yoke down if needed.... I wonder if that heat put into it when cutting would affect strength? The 31 spline yokes appear to be a little longer maybe?

redls1T/A

thats weird, i actually think i need a longer driveshaft, but then again i got a strange slip yoke that appeared to be shorter

showdog75

iTrader: (8)

Cut it with a port-a-band or similar instead of a cut off wheel. I wouldn't think a saw cut wood affect the heat treat.

wannafbody

iTrader: (2)

Find someone with a lathe

dgcustomz

iTrader: (127)

I've installed more than a dozen Magnum F units into 4th gens and have never had this issue. I am using Sonnax 3-3-2491hp

Zanie

Reviving this thread because there is a special Sonnax yoke for the Magnum F, part #T3-3- 2491S .
Its 0.97 inches shorter than the Sonnax 3-3-2491HP

I was tearing my hair out trying to figure out why my stuff didn't fit right .....and I stumbled across it.

Che70velle

iTrader: (6)

Good to know sir. I simply used the yoke that came with my f-body magnum. I bet it was the wrong one.

Mgill

iTrader: (4)

Bumping this old thread up again lol. Got my magnum f installed and using the sonnax yoke for the magnum f and it only goes about 2inches into the transmission, this does not seem right. Called tremec and they said it should go all th way in. Anyone have any suggestions? I'll be checking the splines on the yoke for burrs.

tnmotown

iTrader: (107)

I'll chime in because I just finished my Magnum F swap recently.

I had no issues putting my stock driveshaft back in. Of course, I had to swap the slip yoke and u-joint that I bought from Tick Performance

The yoke is a Sonar T3-3-2491HP and the u-joint was an SKF UJ447. Had everything balanced and it's been performing flawlessly.

Do you have the right slip yoke?

Mgill

iTrader: (4)

Shop owner went in yesterday to work on it and I went and helped him out with it. Was an issue with the sonnex yoke used a strange 31 spline instead and it worked fine.
Was using sonnax: T3-3-2491S

Chased

This is the yoke that came with my unit from Hawks.......What U-joint are you guys using? Part number?

Dan45

iTrader: (6)

What is everyone running for rear ends with this trans? I have Strange S60 with Mag F trans… everything bolted up EXCEPT the shaft! It’s about an 1” too long! Doesn’t go into rear yoke. I did just as all adjustable rear arms, panted and short to arm… wondering IF the suspension has affected DS length?

Azgeodude

Hiya. So, with this Magnum-F specific Sonnax yoke, does that effectively fix the length issue so the same driveshaft can be used? It sure sounds like it.