Neil B

Hey guys, I'm getting my car ready for some additional horsepower and just tackled a pinion seal and driveshaft upgrade. I have a 4 post lift and debated using it, but ultimately I decided to do this on jack stands to allow for unloading the suspension. It is totally doable with the diff in the car, but there is not a lot of room to work. I used a Summit Racing pinion yoke holding tool, but you could easily fabricate something. This tool just barely cleared the front diff mounting flange. To drive in the new seal, I used 1 1/4" galvanized pipe with a floor flange. You need about a 12" pipe extension in order to clear the frame crossmember.

At the same time, I upgraded the driveshaft to a 2.5" .095 wall shaft with 1330 solid ujoints from Ft. Wayne Clutch and Driveline. I ordered my custom length driveshaft last Thursday and it was on my doorstep on Monday.

The 1330 slip yoke interfered with the e Brake cable and pulley so I had to move that over a bit as well.

GTR1999

Nice job Neil. Those shafts look sharp. We had some custom shafts made for our track car as well only I went with 1350 yokes and 1480 12 bolt. What required the change, HP upgrades? What did you use to seal the splines?

You are correct the pinion can be done in the car but it's tricky. Interesting you didn't use the lift? I think that would have what I used with some supports.

Neil B

Yes, I'm upgrading the engine from the current 468 big block to a new 515. I have a separate thread on that. I realize I'll have more drive train upgrades in the future but this gives me a little piece of mind since I had to address the leak anyway. It would take a fair bit of clearancing to fit a 1350 u joint on my car. I used Permatex #2 on the splines and RTV on the outside of the seal body. There was nothing on the old seal.

I didn't use the lift because I knew I'd have to rotate the pinion. I also didn't know how the diff would react with the weight of the car when I dropped the front diff support. I have put the rear on jack stands (on the lift) before but it was just too sketchy for me. What finally sold me on doing it from the ground was if I couldn't get the seal out or back in and had to remove the diff from the car.

GTR1999

You got it done, that's what counts. I used to use #2 on the splines, it does work. I think I most likely had it referenced in my old how-to threads as well. I use a different product now but as long as you have the #2 on it then it should be fine.

Good luck with the build.

BlackC3vette

Hello GTR1999
So what product are you currently using to seal the splines?

GTR1999

Permatex Permashield. Use it both splines, let degas a few minutes and assemble. I knew a Permatex tech engineer and he recommended it to me several years ago and I have used it on every diff since, no problems and I have them around the world. #2 is good and I have used it on a lot as well.

drspencer

Do I apply the #2 Permatex to the splines of the flange, or the splines of the shaft that pokes out of the differential?

Thanks.

drspencer

That's a clever tool you made to drive in the new seal.

I'm curious, why is it wrapped in blue painters tape? Are those pieces not threaded together?

Thanks

GTR1999

I made some changes on sealing but can't post it as it might be considered solicitation. You have my contact info, reach out to me before you buy any RTV or #2

Rescue Rogers

I would guess the tape is to prevent scratches on his fresh looking paint