CV driveshafts for CJ7?

[Oldguyinajeep]

I'm thinking about upgrading to a Rubicon Express 4.5" lift kit with YJ springs. They suggest CV driveshafts. Does anyone know if I can simply get shafts from a later model jeep, or will I have to have the driveshafts made?

 

[BusaDave9]

getting the right length is critical. I don't think you'll be able to find one just the right length. You can have the length modified but I would get a new one from Tom Wood's Custom Drive Shafts - Tail Shaft Conversion Kits
Measure the compressed and extended length without a driveshaft installed.

 

[Posi]

As an option you could use a front explorer driveshaft. I found one for $20 at the boneyard to use in the rear. Had a few inches added to make it 33.5” (105WB).

The ford stock shaft is 2" diameter .120 wall and has a 2.5 stroke. I added some length and 4.5 stroke. If your rig is more on the stock side you would be good with just cutting down the length. You would need a 1310 cv yoke at the Transfer Case with any cv driveshaft as well.

 

[Old Dog]

^^ I agree with what they said. The front shaft from a XJ will also work,(I have one cut down in the rear of mine) but as with the explorer shaft it will need to be made to the correct length.

In all reality by the time you buy new joints and maybe have to rebuild the cv, get it cut and rebalanced ,a new shaft from Tom starts looking like a good deal.

 

[Torxhead]

By installing the rear cv joint, you will not have to lower the Transfer Case as required in the 4" plus lift kits but the pinion angle does have to be in line with the drive shaft angle.

 

[Oldguyinajeep]

I agree that having a new shaft built is probably the way I'll go. Regarding the pinion angle, I read in the Tom Woods literature the same thing that Torxhead said about "pitching" the differential. So this will involve a little more work than I thought. I'll have to cut off and re-weld the spring perches at the new angle, right?

This brings up a couple of questions: first, are new spring perches available aftermarket, in case I jack them up too much removing them?
Second: my welding skills are pretty good, but not great. Are welds here critical? It seems to me that the welds on the perches don't take a lot of stress after the axle bolts are tightened.
Third: can the spring perches be welded to the axle tubes in place, if I drain the fluid and remove the diff cover to allow for gas escape, or am I asking for trouble?

This may seem like a silly question, but I'm assuming that I'm going to need new shafts on both front and rear, and will need to pitch both diffs, right? If so, is there enough clearance between the front shaft and the skid plate, or am I going to need to cut it up some?

 

[Oldguyinajeep]

Old Dog, it looks like you've already been down the trail I'm headed. I see you've done the RE4.5 lift. I currently have a 2.5 Rancho with a 1" body lift, running 35s. Do you think the 4.5 lift was a worthwhile mod?

Also, I wonder about flipping the u-bolts. I currently have Warrior skid plates on the bottoms of the springs, and they've done well. Would I have anything further to gain by flipping the bolts while I have everything apart?

 

[CJ007]

I went with Adams drive shaft. They are online and eBay. You can bid a little lower than price and should get. Spicer ujoints and custom made. Call them if you want to double check measurements or need help. I got excellent service and great price. I think like $215 out the door and it went right in. Even came with a cool t-shirt.

I run moderate to hard trails and have not had any issues since installing. Have run at least 1 yr.

 

[Old Dog]

I think mine is a little taller than I want right now. I have 4 rear springs on mine, I should have went 4 front's as they are 5 springs and the rears are 6. I also have a 1" body lift and 1/2" shackles.

I have cv shaft in the rear but not the front.

Here's a pic. of the u-bolt filp from Dynatrac I use. And one of it now setting on 35's.

 

[Oldguyinajeep]

I'm still curious about the pitching of the diff. Did you do this yourself, or have it done at an axle shop?

 

[CJ007]

I cut my leaf mounts off and did my own. Research a little. I know busadave or someone has posted before so u can search and it is on one of the websites (tomwoods?) Tellls u what degree etc.

 

[BusaDave9]

Basically you do just remove the spring purches and re-weld them.
Here's what I once posted on the topic:

Let me add a couple notes on drive line angles.
If the U Joint angles on a drive shaft are not strait (they never are on an off road vehicle) then they actually speed up and slow down on each rotation. This can produce a bad vibration. But a drive shaft is made so the vibration of the front U Joint cancels the vibration of the rear U Joint. This works great if the the angle of the front U Joint to match the rear. This is how every manufacture makes vehicles.

But this only works at small drive line angles. The UJoints don't like too much angle so when you lift your jeep you may have to angle the rear differential upward. This can be done with angled shims at the leaf springs. Then to keep both u Joint angles the same you can lower your TCase. If the drive line angles get to be too much you should then go to double cardan joint or a CV joint at the front of the drive shaft. A double cardan joint is 2 U Joints together.

These 2 U Joints cancel each others vibrations. In that case the U Joint at the differential should not have any angle. To keep it from vibrating it should be strait like this.

Now you can see how the pinion is much higher than the manufacturer intended.
That vent reservoir is a good idea. Thanks for the tip.

Here's the rest of the thread: http://www.jeep-cj.com/forums/f2/high-pinion-angle-keeping-pinion-bearings-lubed-7529/#post64224