Tom Wood Driveshaft Questions

Chris

Administrator
Staff Member
Ride of the Month Winner
Joined
Sep 28, 2015
Messages
71,236
Location
Gillette, WY
I'm going to be replacing my 2.5" OME lift with a 4" Currie short arm lift, complete with fully adjustable Currie control arms including double adjustable uppers.

In addition to that I have a1.25" BL and 1" MML.

I realize my stock drive shafts will not cut it any longer and I need to have Tom Wood make me some custom shafts.

I'm very confused though about what I need to order. Do I need a front driveshaft and a rear, or just the rear?

In addition to that, they have so many options on their website for driveshafts that I'm just totally lost. Ideally I want to order the best of the best since I don't like to skimp when it comes to my mods.

Last but not least, my TJ is a Rubicon so it has the NP241OR transfer case with the fixed yoke.
 
You won't need a front drive shaft.
Call them and they will walk you through all of the options. I have a thread floating around in WF where I posted some information that I found.
 
  • Like
Reactions: Chris
Exactly, only a rear driveshaft will be needed. The front driveshaft is so long that it is barely affected by the suspension lift height.

Good to know. I was under the impression I would need both a front and rear driveshaft.
 
You shouldn’t really need to do anything with your front drive shaft. That is of course, assuming everything in the front drive shaft is otherwise in good working order.

For the rear drive shaft though, I would suggest running a double cardan drive shaft. In order for this type of drive shaft to run smoothly, you will want to pitch the differential so that the pinion points directly at the output of the transfer case (maintaining 3 degrees, or less, a joint angle at the differential end (see the art below). For example; if the slope of the drive shaft is 15° the pinion should be between 12° and 15°. With 13° or 14° being ideal. Again, this is just an example and your actual numbers will probably be different.
Double_Cardan_driveshaft.gif

For the rear drive shaft, we have a couple of options available. Our 1310 series double cardan drive shaft is $299.00. Our 1350 series double cardan drive shaft is $429.00. We have had very good success with our 1310 series. It does flex about 5° more than a 1350 series and unless you are going to beat the ‘holy bejebas’ out of the vehicle, I think the 1310 series would serve you well.

If you have not already done so, please take a moment to review the information at this link: http://www.4xshaft.com/rubicon/rubicon_rear.asp

There you will also see the reference measurement, for length that we like to have. This is from the face of the out-put flange on the transfer case to the face of the yoke on the differential. This measurement should be taken with the suspension normally loaded (static ride height). Your tape measure should also follow the approximate slope of the drive shaft, going straight from point to point (no bend in the tape measure) and it should be done at about the 3 or 9 O’clock positions at each end (center height). If you take the measurement as things sit now and also inform us of your intention for additional lift when ordering, we can make the necessary compensations for the expected length change and assure you a good fitting drive shaft after you install the lift.

In addition to the drive shaft, I will suggest a new set of straps & bolts to attach the drive shaft to the pinion yoke. The reason is; the bearing straps are designed to draw down to clamp the bearing cap in place. After repeated use, these straps loose some of the draw down effect. A new set of straps & bolts is just $6.00.

Once the product is ordered, it will ship the following business day. We pay freight (UPS Ground, lower 48 states). However, we do add on a $10.00 packaging & processing charge.

If you have other questions or would like to place an order, it may be best to call. Our Toll Free US # is 1-877-497-4238. Our worldwide telephone # is 1-801-737-0757. Hours of operation are 8:00 AM - 5:00 PM. Mountain Time Zone. (GMT - 7 hours) Monday through Friday. If you cannot call, let me know and I will send you alternative ordering instructions.

Lastly, if you would like to post my reply to you on the site, I think I would appreciate it. After all, it is much easier for me to educate the masses, rather than one person at a time. I am happy though, to do either.
 
  • Like
Reactions: MaloStapalo
I wasn't aware that the rear pinion needed to be at an angle with the double cardan driveshaft! If the rear pinion is at an angle like that does it cause any issues with the rear springs not sitting properly in their perches? I assume if so it could be fixed with some shims.

At this point I haven't yet installed my new lift kit (I switched to a 4" Currie lift with adjustable control arms) so I assume that it would be premature for me to place an order and measure things until the new lift is installed, is that correct?
 
I wasn't aware that the rear pinion needed to be at an angle with the double cardan driveshaft! If the rear pinion is at an angle like that does it cause any issues with the rear springs not sitting properly in their perches? I assume if so it could be fixed with some shims.

I believe you have coil springs in the vehicle. Shims would only be used with leaf springs. It may be that the new lift, if it comes with new control arms, are the correct length to set your pinion properly. Or it could be that the lift comes with adjustable control arms. If it is either of these, you will have what you need. If not, you may need to get some adjustable control arms.

At this point I haven't yet installed my new lift kit (I switched to a 4" Currie lift with adjustable control arms) so I assume that it would be premature for me to place an order and measure things until the new lift is installed, is that correct?

While it is generally best to have the lift installed prior to taking any length measurement, as I previously stated; "If you take the measurement as things sit now and also inform us of your intention for additional lift when ordering, we can make the necessary compensations for the expected length change and assure you a good fitting drive shaft after you install the lift."
 
VERY nice to have you here Tom! People, notice how well he explains everything... he's just like that on the phone and will make the whole experience a very pleasant one. I think it was something like 15 years ago I purchased my first rear driveshaft from him, I'd never go anywhere else.
 
Last edited:
  • Like
Reactions: Adms01TJ
Okay, ordered my driveshaft from Tom Wood a few hours ago.

I ordered the 1310 instead of the 1350 since the 1350 is probably massive overkill for most of us.

I over thought this entire driveshaft thing and made it much more confusing than it needed to be. Following the diagram below (for 03-06 Rubicons) on Tom's site I used this procedure and measured my driveshaft to be 17.25". Other than the measurement below there was nothing else I needed to measure.

RubiconMeasure_575x230.jpg


I told them that I was soon going to be going from a 2.5" lift to a Currie 4" lift, so they said they'd add an extra .25" on the driveshaft for me which should compensate for that extra lift.

Can't wait to install this bad boy! Now I think I'm pretty much good to go for when I install my Currie 4" short arm suspension!
 
One thing that confuses me is why they even need a driveshaft measurement from the stock driveshaft when these new driveshafts have the ability to extend in length?

I didn't realize that until I got my Tom Wood driveshaft today and started playing with it and noticing that the length of it will extend significantly if you want.
 
One thing that confuses me is why they even need a driveshaft measurement from the stock driveshaft when these new driveshafts have the ability to extend in length?
Because you want the length so the slip-joint is in the middle of its available travel at normal drive height. So the driveshaft can expand and contract equally in both directions as the suspension flexes up-down/axle moves around.
 
  • Like
Reactions: Chris and Kevin E
Because you want the length so the slip-joint is in the middle of its available travel at normal drive height. So the driveshaft can expand and contract equally in both directions as the suspension flexes up-down/axle moves around.

Ahhhh, that makes sense!
 
For example; if the slope of the drive shaft is 15° the pinion should be between 12° and 15°. With 13° or 14° being ideal. Again, this is just an example and your actual numbers will probably be different.

What's the reason for the pinion being at slightly less of an angle than the driveshaft? Why wouldn't the pinion be at 15° to match with the driveshaft?

Just curious why there's the slight angle difference with the pinion.
 
What's the reason for the pinion being at slightly less of an angle than the driveshaft? Why wouldn't the pinion be at 15° to match with the driveshaft?

Just curious why there's the slight angle difference with the pinion.

I'm curious about this myself...
 
What's the reason for the pinion being at slightly less of an angle than the driveshaft? Why wouldn't the pinion be at 15° to match with the driveshaft?

Just curious why there's the slight angle difference with the pinion.
The reason is that torque through the axle during acceleration slightly lifts the pinion angle upward. More so with leaf spring suspensions and less so with control arms but it still lifts slightly even with control arms. So if the pinion angle is even a tad too high to begin with, it could cause vibrations when lifted even slightly more during acceleration. :)
 
  • Like
Reactions: Serbonze and Chris
The reason is that torque through the axle during acceleration slightly lifts the pinion angle upward. More so with leaf spring suspensions and less so with control arms but it still lifts slightly even with control arms. So if the pinion angle is even a tad too high to begin with, it could cause vibrations when lifted even slightly more during acceleration. :)

That's what I figured Jerry, but wasn't certain. Makes perfect sense now that I think about it!