Topic: Rear driveshaft question

[KDXSR5]

Will my 90 reg cab short bed driveshaft work on my 85 reg cab short bed? Just wondering if it was worth keeping as a spare.

[46&2]

Will my 90 reg cab short bed driveshaft work on my 85 reg cab short bed? Just wondering if it was worth keeping as a spare.

Try and bolt it up and see.

[KDXSR5 [OP]]

cant right now, can't find the 90 shaft, lol

[jimbo74]

cant right now, can't find the 90 shaft, lol

then i guess you should keep it......

[83MT]

Measure? I know the wheelbase changed a bit throughout the years, as well as the transmission lengths....but they may have stayed the same on those years. I'd just get a tape measure out.

[*ROKTOY*]

Think the bolt pattern may be different.

[DTB]

Think the bolt pattern may be different.

x2 fo sho

[83MT]

But you can always drill, right? If you're willing to go that route..

[RN37DD]

if the 85 has the 10mm bolts it should bolt up. i couldn't use my 79 driveline on a 92 axle flange, because the 79 had 8mm bolts and was different. found a ifs front driveshaft  laying around with 10mm holes. removed the flange and installed it on the old rear driveline. works perfect.  hey if you measure you drive shafts post your results. I'm going to need new driveshafts after i finish a tranny mod.

[KDXSR5 [OP]]

Ill see if I can find the rear shaft. I have the front ifs shaft laying around somewhere as well, I plan to clearance the CV and run CVs front and rear after I get duals.

[OOPS]

In a situation like this, a tape measure is your friend. That is if you can find the shaft!!!!!!!!

[KDXSR5 [OP]]

I was more worried about the flanges being off than anything else, but I will measure it and see

[Rocksurfer]

Everything will be the same except for the flange mount holes, they will not line up but you can redrill the flange so the holes will line up. I had to do this when I used one out of an 86 for my 85. I think the change came when they went to IFS. Length was not an issue at all.

[KDXSR5 [OP]]

90 rear measures about 44 inches collapsed and around 47.5 inches extended to right before the splines are showing. Simple math shows about 3.5 inches of slip. Flange to flange on my mildly lifted 85 is about 46 inches. So it should work besides the flanges being a little off. If I ever need it I guess I have it. The only reason why I am looking at keeping the 90 rear driveshaft is because the u-joints on it have only about 6000 miles on them. The ones on the 85 I assume are stock with around 160,000 or something like that on them. If they ever go bad I can just swap driveshafts.

[46&2]

90 rear measures about 44 inches collapsed and around 47.5 inches extended to right before the splines are showing. Simple math shows about 3.5 inches of slip. Flange to flange on my mildly lifted 85 is about 46 inches. So it should work besides the flanges being a little off. If I ever need it I guess I have it. The only reason why I am looking at keeping the 90 rear driveshaft is because the u-joints on it have only about 6000 miles on them. The ones on the 85 I assume are stock with around 160,000 or something like that on them. If they ever go bad I can just swap driveshafts.

Having extra drive shafts is never a bad thing

[RN37DD]

2x on that. thanks for the measurement info. i'll check the length on my swb 79 driveshaft. i'm guessing it's around 48 inch.