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View Full Version : ...on to driveshafts...


Fuzzydog
04-12-2007, 10:55 AM
I have temporarily addressed my gear swap issue - not ideally but temporarily.

I built my own rear driveshaft to compensate for the SYE I put on my 242 tcase and 6.5" lift. I used a grand cherokee front driveshaft which is slightly longer than my XJ 242/AW4 front shaft but it is a slightly smaller diameter tubing. Does anyone have info/references/links on the importance of driveshaft diameter tubing?

TIA

In The Zone
04-12-2007, 11:17 AM
diameter will not matter to much in your application, typically over a length a larger diameter is going to support more load dynamically a thinner diameter will not matter on a application such as yours as long as wall thickness is increased according to diameter reduction

ie 3" dia shaft with .120 wall vs a 2" diameter shaft with wall thickness .187 ect..... I have ftypically found the smaller diameter shafts having thicker wall..

if any thing yoour shaft will have some what more clearance
the only draw back i could think of would be u joint size...

Fuzzydog
04-12-2007, 11:45 AM
Thanks Zone! that's pretty much along the lines of what I was thinking too - its just good to hear/read it from someone else too.

The GC driveshaft has not been lengthened at all, it is stock length so if that was ok for a GC I can't see how it would be too weak for an XJ. I was thinking too that since I have the 242 tcase i might just keep it in full time 4x4 anytime off road (and even on road for that matter), that will split some of the torque to the front driveshaft...
tires (for now) are 31" BFG MTRs and I typically have a light right foot.:o

we'll find out how it holds up this weekend.

FWIW the grand cherokee DS is about 36" long and the XJ is about 34"

DirtyComanche
04-12-2007, 12:42 PM
Do you know what tubing is used on the GC shaft?


The XJ front shafts are 2x.120. They seem to hold up alright in the rear.

Fuzzydog
04-12-2007, 12:53 PM
no idea about the tube but it is definitely a slightly smaller diameter. I'll measure it tonight and let you know. as for the wall thickness.....I guess I'd have to cut it open and that ain't gonna happen (I only have 1 of them)

BTW, i was at the Chilliwack PNP last friday and scored a driveshaft out of an 82 Mercury Cougar XR7.....this is one of the (few) vehicles that has the spicer CV flange that bolts to the RE SYE flange and to the XJ/WJ driveshaft. I couldn't believe that I actually found one. cheapest cost I could get for just the flange locally was $117 plus tax. PNP - I paid $27.95 (or was it $24.95) for the whole driveshaft. I'm going to run the GC front shaft as a rear for a bit and if there are any probs I'll just get the cougar shaft shortened (considerably!) and a slip joint put in. That cougar shaft (oh behave!) is some huge diameter