Well I did it,blew my 7.5 rearend friday night in my 69 1/2. Have a 8" from a 76 automatic. The drive shaft that came out along with it is much longer than the drive shaft matched with the 7.5 and manual 3 speed. I have a top loader( RUG E2) also sitting there so I figured might as well do it all right now while it's all apart and up on jack stands. The top loader is a 28 spline. Does anybody know off hand how many splines on the automatic yoke and if it will work with the top loader. How long will the auto drive shaft have to be shortened? Maybe the original shaft from the 7.5 manual will bolt up to the 8' and top loader? The 8" is a 5 lug. From reading blogs I found that a 4 lug axle will replace the 5 lug as long as it's from a 8" rear. Since my weels are 4 lug I was considering making a swap. Does anyone see disadvantages in doing this? Any and all help would be appriciated. I'm also taking the 8" down to the new rear end shop at Foster Auto Parts in Portland Or. to see about getting some gears and posi-traction. I'm thinking about 3.25 for some improved performance without wearing the engine out to soon. Any Mav roders in the Portland area have any better suggestions as to where to take it?
I don't know about the toploader (I have heard that the driveshaft is no diffrent then an automatic, but don't quote me on that). I did find that a driveshaft froma '73 automatic car was about an inch to long for my '69 1/2, which leads me to believe that the 7.5 rear makes a diffrence. However, you might be alright. I'd just start putting the thing together and find out. And how about some pic's of the 7.5 carnage? :evilsmile The 4 lug axel will NOT work in the 5 lug rearend. The bearing will be to small on it, and the backing blate will not bolt up. We have verified this with measurments and pictures. http://mmb.maverick.to/showthread.php?t=20444&page=2&pp=20&highlight=lug+axel
When I put the 8" 5 lug out of a 75 in my 69 1/2 I used the same drive shaft that was in the car. I did not have to modify anything, it went right in. So you should be OK with the stock drive shaft. Don
when i swapped out my toploader for a c4 i used the same yoke (and same driveshaft), but all i was changing was the trans.
I was wondering about the lenght of the 3 speed trans compared to the 4 speed. I don't have the 3 speed out to compare. Also the drive shaft from the automatic is much bigger in diamiter. I guess that wouldn't matter other then it would be stronger.
The 3 and 4spd are the same length unless its a long tail 4spd. It should be 24 inches were bell bolts against to tip of tail. Also on my 70 the one shift rod rubbed on the tunnel above the trans crossmember. It was easy to fix though as for the D shaft you might have a 4dr shaft they are longer. As for the yokes they will work for a c4,t5 3and4 spd and srod atleast they did for me.
If you're talking about mine, no, I personally took it out of a '73 2 door C4/ 8 inch 5 lug car where it fit perfect. The driveshaft fit the '69 1/2, but BARELY and was bottomed out in the transmission, makeing it very hard to get it in the rearend. I had to take the caps off the rear U joint in order to work the shaft up into the input shaft of the rearend, that's how tight it was. I didn't even try to drive it like that, and went to the junkyard and got a driveshaft from another '70 with a 7.5. It fits fine.
ya, the d shaft came out of a 4 door but it sounds like the 7.5 shaft will work for me. Thanks everyone. I'll open the case up tomorrow on the blown 7.5 and take some pictures.
I have a c-4 and I will replace it with a toploaded but I don't know if I have to replase the driveshaft . can some one tell me:confused: I hope I can use the same driveshaft with out cutting it. thanks.
Same driveshaft, yoke, crossmember, etc... Just use it all from your C4. As stated above, it must be a short tail Toploader! The short tail was intentionally made to use the same stuff as a C4, the long tail was engineered to use C6 stuff. On that RUG E2, you got the right tail shaft. It is same length as C4. You definately got the right ratios for street driving with the 'wide ratio'. The only thing to watch for is shifter fitment. All those toploaders use different mounting locations for the shifter, and each must have the right parts to work. The short tail had at least 3 different mount styles, 5 if you include the later o/d versions. Best to order the shifter for the car the tranny came out of... I learned the hard way. Got a spare shifter now cuz it didn't fit the tailshaft I was using. Good luck Dave
