D30 Upgrade

I just read this whole thread and learned a lot about upgrading a Dana model 30. Awesome stuff, thanks for everyone input

 

It drove it yesterday! I have between 3/8" and 1/4" toe in. I need to drive it a little more and measure again. It seems to be more sensitive to the road than my old axle. The roads in Ca. suck and it picks up every little groove and it is harder to control. I am going to crawl around and make sure everything is tight again. I did not get a chance to take it in the dirt yet or try out the ARB, that may not happen until June at this point. More info after I try it.

 

Just figure I'd update, I may end up needing a front driveshaft. I dont like my uptravel left in the stock shaft (F134/T90/S18). It bolts up, but there isnt much left.

 

Once the toe is set correctly, road manners should be okay.

 

About 1/8"?

 

Sounds good to me.

 

I'm pretty sure my D27 was 1/8".

 

Factory 27 spec was 3/64" to 3/32" FYI
My eyes wouldn't be that great on that tape measure.....

 

Makes 2 of us! Hope to get to it tomorrow sometime.

 

You should check your caster if you have a wandering Jeep. It is more likely the culprit than toe in. I'm springover, although I don't think that matters, but I set my caster at 6 deg. and it tracks very well.

 

Set the toe in at about 1/8" last night and it seems to have helped quite a bit. I may try to get it even a little closer to what Jim stated. I am trying to figure the caster. From what I can tell it may be 10 degrees positive. Need to play with it a little more and find the best way to figure it.

 

I just measured and I am at 0 or 1 degree positive. Now I need to figure what size shims to get.

 

If your zero or 1 positive........a 4 or 5 degree shim should be right there....

 

Thanks Tarry,
That helps a lot. I'll look around for some.

 

Just so we're on the same page.........3-5 degrees positive although 5 is fine , but also check your pinion angle up front as the pinion will go down under acceleration.........which could increase caster.

 

Thanks Tarry,
I'll check the pinion angle today.

 

Wouldn't that only really apply to a driven axle? Given that this will only likely be driven at low speeds off road, I wouldn't be worried so much about increasing caster under acceleration as I would U-joint bind... At least in that scenario. Not much you can do about it though besides cut and weld if it's that far off when the caster is set correctly.

 

Well that is a driven axle when engaged.................But Yes , In a PM to Jeff previously I told him it was best to measure both the caster and the driveline angles and slope and shoot for a wedge adjustment that creates a Happy Medium between the two angled needs............caster and U-joints.

 

I guess my point was that it's only engaged (driven) typically at low speeds (and dirt) so a change in caster in that situation would be far less critical than U-joint bind... In other words, set the caster correctly for the street when that axle isn't engaged, just make sure it won't bind off road and all should be good. I wouldn't take caster change when engaged into much consideration in an old CJ.

 

Attached is a picture of the pinion at ride height with full weight, at approximately 10 degrees. From what I have read and researched the caster is important at between 5 - 7 degrees positive. I am going to try and get the caster at 5 positive. I have some 4 degree shims on the way. After the new shims are in I will make sure the toe in is 1/8" or possibly a little less if I can get it that close.