Need Help! Drive Shaft

Fast Ed

Fast Ed

Member #076
GCC Member
Location (City)
Lake St. Louis
First Name
Ed
Last Name
Jasper
Got the car up on stands and found my main leak, the rear transmission seal. My concern now is the drive shaft feels pretty sloppy going in and does not seem to go far enough in to me? also the angle seems to be to much? Does anyone know the correct pinion angle? and typical length of drive shaft? Here are some pics.

Thanks Ed
314-607-2081
 
Ed, That does look short on engagement. I know most say that you should have a minimum of 3/4" of play left on the end of the driveshaft yoke so that when the pumpkin travels up and down that the driveshaft doesn't bottom out on the transmission output shaft. so if you had maybe up to an inch of play you'd probably be good. I'm in the process of putting my engine and a new trans back in my FFR. The new yoke is shorter. Once it is all in I'll be able to accurately measure my engagement and decide if I need my driveshaft lengthened. MPTech has his driveshaft modified in the Arnold area and both MMarshall (Mike) and Itzdapig (Keith) had their driveshaft modified in or around St. Charles. I don't remember where you are, but you can contact any of these guys and they could point you to the right place. I'm going to use the place in Arnold.

Here's a link on ffcars for the pinion angle:
http://www.ffcars.com/forums/17-factory-five-roadsters/463890-pinion-angle-help.html
 
I think you said you're running an IRS??
If that's the case, then the pinion angle isn't really relevant, as well as rear-end travel.
I'd look into a longer driveshaft and reducing the transmisson mount height (looks like the tailshaft is sitting too high to me. I don't remember my driveshaft having quite that angle, I'll see if I can find or take a picture.
How much clearance do you have between the tailshaft and the 4" chassis tube running side-to-side? Can you drop it down a bit?


Nevermind, I had your car confused with Keith's! I see you are running a straight axle. My bad.
 
Were the pics taken of the rear axle supported on jack stands carrying the weight of the car? I also have a solid axle....let me know what measurements you need.
 
.

Looks like a live axle to me - and the driveshaft appears to be about 1-1/2" too short.

I used Driveshafts Unlimited in Arnold. They have a measurement sheet they give and look for a measurement from the tailshaft to the CL of the rear universal. As I recall, you put the yoke into the transmission all the way, then pull it out 1/2" and then measure between the U-Joint centers. If the suspension is designed correctly (Someone hasn't modified the original design), you should have less than 1/2" movement fore and aft as the axle moves up and down.


Driveshafts, Unlimited
3608 Market, Arnold, MO 63010
(636) 296-2841​

My 2c

Paul
 
Last edited:
Inland truck and transmission in Saint Charles.
On Portwest just off 94 south of 70.

Definitely looks short, angle is hard to tell from the photos. Do you have adjustable control arms to change the angle if needed?
 
Thanks for all the comments guys! Since I didn't build the car I am a little in the dark. My understanding I have a 3 link. I put a jack under the rear end looks like ride height is close so I need to get the angle correct before I determine if shaft is to short. Mike Marshall gave me a call so if I adjust control arm in pic. should move down. Not quite sure how to measure angle?Also has anyone put a rear seal in a TKO600? I wounder if Island Truck and Transmission would do seal and drive shaft but still need angle done first.
 
Where are you located?
Doh, see you are in Ofallon now that I looked.
we can get the angle set. I am off all this week, give me a call. 3146408911 Keith
 
Last edited:
Remember, you aren't measuring the angle of the driveshaft, but the difference in the angle between the u-joint at the transmission and the u-joint on the pinion. It should be about 1.5* difference.
Looking at picture #5 in your first post, I'm going to say you have a shaft for a T-5, not a TKO600, it looks too short. I think that is why you have an oil leak, the shaft may be wobbling around on the tranny shaft. Hope that hasn't damaged the rear sleeve on the tail-shaft. Looking at my build manual, (yes I use one) the driveshaft for TKO transmissions are at least 1.5" longer.
 
OOOPs, the extra 1.5" was for a coupe, my mistake. BUT that still looks too short????
 
I have most of the receipts for the build of my car receipt says TKO600 with shortened input shaft. Motor is a 552 big block ford 460 bored & stroked.
 
Off tomorrow I am going to try to work on setting angle and getting correct drive shaft length. If anyone wants to lend their expertise, another set of eyes would be appreciated.
 
7457 Pierside Dr. Ofallon Mo. 63368

I am open if some has a good time they can come over. I will set it for then.
Thanks
 
You must log in or register to reply here.
Back
Top