Pinion Blocks

I had to remove the pinion angle blocks to fix some bad vibration and have a question. Now that the wedges are out it raised the jeep up about 3/4". I don't want to add too much angle on the short drive shaft so do I need to add flat blocks or should I be okay?

 

As long as your u-joint angles, both of them, are ok it won’t matter.

 

What you really need to look at is the angle between the driveshaft and the pinion yoke at full droop. Pretty easy to have an excessive angle with any lift and a short driveshaft. IMO, you want less than 20 degrees. You may need to reinstall the degree shims.

Is the driveshaft just regular U-joints on both ends or does it have a double cardan joint on one end? That makes a difference as to whether you want the equal angles Nick references on the former or whether you want the pinion aimed directly at the transfercase yoke in the latter.

 

It's the original driveshaft and it at 25 degrees. The transfer case yoke and pinion yoke are within 2 to 3 degrees of each other. I need to replace the transmission mount to get a more accurate measurement. So, reinstall the degree shims and install a double cardan joint shaft? I looked at them. I also am thinking of removing the 3/4" shackle lift and go stock. Not sure what I would gain from that.

 

With a 2 1/2 lift on 1975 CJ my transfer case u-joint would go out about every 5-6000 thousand miles. Got real good at changing them on a curb with a socket and hammer. Always
carried spares. A shim would work but only with a double cardan. You want your pinion pointed at just below the transfer case yoke center. These days, I would cut and
re-weld the spring perches for the correct angle and order a good shaft form Tom Woods or your preferred manufacturer. Woods has done hundreds of these and knows exactly what
you need. They seem real nice to deal with. The dana 20 creates a much steeper angle on short driveshaft as opposed to the dana 18. The other thing to do is drop your transfer case
mount on the frame to correct your angles. This can create other problems. Less clearance on height, fan to radiator unknown stuff and twisted motor mounts. Kind of a pick your poison.

I will use the double cardan on my 18 when I have everything sorted. Already turned the axles.

 

I was looking at a double cardan driveshaft and yoke for the Dana 20 from Tom Woods today.It sounds like the best way to go.

 

My double cardan driveshaft from Tom Woods is only 14 1/2 inches long. It works just fine, even with the LS providing way more power then the Jeep needs.

 

As soon as I can reinstall the wedges so I can get an accurate measurement, I will order a double cardan shaft from Woods.

 

Ordered the double cardan drive shaft and yoke from Woods.

 

Did you end up with the 2" travel on the splines? I need to order one slightly shorter for my 3B. That one is looking like 12 3/4 to 14 3/4" and I still need a limit strap to keep the pinion angle to 20 degrees at full droop. That is with a D18------

 

I

I don't know how much travel it has on the splines. They just wanted the measurement at ride height. I'm also using a Dana 18, but haven't checked the driveshaft angles at full droop. I'm running stockfish 7 or so inches of travel rear shocks, and it's in the middle of the stroke, so likely only 3-4 inches of down travel at the shock and 4-6 at the wheel. My wife drives the CJ5 more than I do and the Jeep is really a street queen. I built my JK for off-road and it gets used accordingly.

Mike

 

I got the full spline shaft. My measurement was 18-1/8" with the D20 which I measured several times. Not sure of the travel length.

 

I believe Woods requires no less than a 16" driveshaft for {X-spline} long shaft and 13.375" for a standard [S-spline] shaft. From there they go down 10" custom order.

Dana 18 transfer case requires a yoke for Double Carden shaft and the parking brake would no longer be functional. I would phone them to get the right parts before ordering.

 

I already have the double cardan yokes on the D18. Those 10 spline yokes are Dana Spicer 2-4-4061X (NEAPCO N2-4-4061X). Looking at those yokes, the only difference between those and the regular non-ebrake D18 yoke appears to be the machining on the pinion side for the double cardan bolt heads. The dimensions appear identical. I think one could clamp a regular yoke on the mill table and easily make it double cardan compatible. I previously discarded the drum ebrake for Wilwood's MC4 disc versions.

 

Thanks. That is good info. Not everyone has the talent or machinery to do that though. I have gone to the rear e-brake already and it does
eliminate the oil on pads with the sacrifice of hanging cables. They offer the yoke for $90 and doing a quick check, I could not find it cheaper.
This is a good sign that they don't rip your rear locker on pricing. Had chat with them a few months back and they seem cool to deal with.

Love that Jeep! You have used every bit of what little room is in it. What do you guesstimate the weight will be? Imagine if all the parts were steel!

I looked at your first album and am waiting for my brain to recover before I open the other!
John

 

You are correct on the length for the X-spline. The D20 does require the yoke for the double cardan shaft and there are two versions, 10 spline and 26 spline, I have the 10 spline yoke.

 

Not sure why you are concerned about pinion angle when at full droop unless there is mechanical binding in your joints/yokes. Similar to concern on front on the front
pinon angles and the percentage of time, speeds, use in four-wheel drive, etc. On topic and curious. Maybe my head is in my rear locker and not picturing your set-up.
Some of the buggy rigs are doing crazier stuff with huge power.
Off topic, Dutton is a reference to the show "Yellowstone" and takes place in Montana. Recommended watching.