Front Drive Shaft Spline Length? Anyone know?

2scoops · March 10, 2011

Does anyone know the length of the splines on the front driveshaft?

Why? I would like to move my front diff forward some & I don't want to run out of driveshaft. I lowered my front diff to increase my droop and to hopefully fit 8.5 inch shocks under the hood without needing limiting straps. After lowering my front diff and cycling the suspension I got a lot of bind due to the fact that as the suspension cycles lower & lower, the front CV's move forward also. This compound angle causes the CV boots to bind badly (once I welded in the diff I was probably a 1/4 inch aft of factory placement). So, I realized if I want to maximize my droop I will need to probaly move the front diff at least 1 inch to 1.5 inches forward of factory placement.

I am not sure how Lenny achieved 14.5 inches of travel in the front suspension. When done, I will be lucky to get 12. With 30 inch tires, the top of my tire is able to reach about 1/4 inch past the tube to which the front fender bolts to. I am limited anymore by the ball joints. So, down travel is all I have left to be able to achieve over 12 inches of travel and like I said, my CV boots bind at about 11 to 12 inches due to the compound angle of the shaft.

Now, everybody scoffed at the price of the Gorilla Axles, but I am calling them today to see what they can do for me. I estimate my axles bind at about 27 degrees. Crawlin T2 said the Gorilla Axles will do 40 degrees. Add in I will be able to turn sharper as well and....

Please don't forget to answer my driveshaft question if you know the answer.

Thanks,

Paul

P.S. I am taking pictures as I go.

CrawlnT2 · March 10, 2011

Does anyone know the length of the splines on the front driveshaft?

Why? I would like to move my front diff forward some & I don't want to run out of driveshaft. I lowered my front diff to increase my droop and to hopefully fit 8.5 inch shocks under the hood without needing limiting straps. After lowering my front diff and cycling the suspension I got a lot of bind due to the fact that as the suspension cycles lower & lower, the front CV's move forward also. This compound angle causes the CV boots to bind badly (once I welded in the diff I was probably a 1/4 inch aft of factory placement). So, I realized if I want to maximize my droop I will need to probaly move the front diff at least 1 inch to 1.5 inches forward of factory placement.

I am not sure how Lenny achieved 14.5 inches of travel in the front suspension. When done, I will be lucky to get 12. With 30 inch tires, the top of my tire is able to reach about 1/4 inch past the tube to which the front fender bolts to. I am limited anymore by the ball joints. So, down travel is all I have left to be able to achieve over 12 inches of travel and like I said, my CV boots bind at about 11 to 12 inches due to the compound angle of the shaft.

Now, everybody scoffed at the price of the Gorilla Axles, but I am calling them today to see what they can do for me. I estimate my axles bind at about 27 degrees. Crawlin T2 said the Gorilla Axles will do 40 degrees. Add in I will be able to turn sharper as well and....

Please don't forget to answer my driveshaft question if you know the answer.

Thanks,

Paul

P.S. I am taking pictures as I go.

I dont know the length. I would say a diveline shop should beable to make your current drive shaft longer. imo

I plan on doing this same mod to my t2. Take lots of pics!

joynergarth · March 10, 2011

Does anyone know the length of the splines on the front driveshaft?

Why? I would like to move my front diff forward some & I don't want to run out of driveshaft. I lowered my front diff to increase my droop and to hopefully fit 8.5 inch shocks under the hood without needing limiting straps. After lowering my front diff and cycling the suspension I got a lot of bind due to the fact that as the suspension cycles lower & lower, the front CV's move forward also. This compound angle causes the CV boots to bind badly (once I welded in the diff I was probably a 1/4 inch aft of factory placement). So, I realized if I want to maximize my droop I will need to probaly move the front diff at least 1 inch to 1.5 inches forward of factory placement.

I am not sure how Lenny achieved 14.5 inches of travel in the front suspension. When done, I will be lucky to get 12. With 30 inch tires, the top of my tire is able to reach about 1/4 inch past the tube to which the front fender bolts to. I am limited anymore by the ball joints. So, down travel is all I have left to be able to achieve over 12 inches of travel and like I said, my CV boots bind at about 11 to 12 inches due to the compound angle of the shaft.

Now, everybody scoffed at the price of the Gorilla Axles, but I am calling them today to see what they can do for me. I estimate my axles bind at about 27 degrees. Crawlin T2 said the Gorilla Axles will do 40 degrees. Add in I will be able to turn sharper as well and....

Please don't forget to answer my driveshaft question if you know the answer.

Thanks,

Paul

P.S. I am taking pictures as I go.

I spoke with Kris and he thinks there is at least 2" of extra spline in the front driveshaft.

Garth

Lenny · March 10, 2011

There are two of us that have 14.5" of travel and it is just that 14.5". The drive shaft won't be long enough I don't beleive. I took out the entire front two piece drive shaft with the center support bearing assembly (about 28 pounds) and replaced it with one piece of, if I remember correctly, 1-3/4 x 1/8 round DOM tubing and welded the cut off splines to each end. Saved about 15 pounds. To do this you have to align the engine with the front diff which was quite easy. I then position doweled the engine mounts and shims under the mouunts to make reinstall in the future a snap. If you were to go this way, let me know and I check the exact tubing I used.

Lenny

2scoops · March 10, 2011

I talked with Casey at Gorilla Axles. As I presumed, he would need a Joyner Axle to see what it would take to build one. Only then can he give a firm price. Unfortunately they are really busy right now due to Mud Nationals and turn around time would be lengthy. He said to get back with him in April.

2scoops · March 10, 2011

There are two of us that have 14.5" of travel and it is just that 14.5". The drive shaft won't be long enough I don't beleive. I took out the entire front two piece drive shaft with the center support bearing assembly (about 28 pounds) and replaced it with one piece of, if I remember correctly, 1-3/4 x 1/8 round DOM tubing and welded the cut off splines to each end. Saved about 15 pounds. To do this you have to align the engine with the front diff which was quite easy. I then position doweled the engine mounts and shims under the mouunts to make reinstall in the future a snap. If you were to go this way, let me know and I check the exact tubing I used.

Lenny

And I don't doubt you. As we know, each one of our Joyners are like a snowflake--not a one the exact same. I will remeasure.

What CV boots are you using...stock? It is the CV boot that is the LIMFAC.

Did you need to balance your front drive shaft? I would love to save 15lbs. What about going to a cv front driveline instead of aligning the motor? Could you eliminate the center support bearing then?

Thanks for the info.

Lenny · March 11, 2011

And I don't doubt you. As we know, each one of our Joyners are like a snowflake--not a one the exact same. I will remeasure.

What CV boots are you using...stock? It is the CV boot that is the LIMFAC.

Did you need to balance your front drive shaft? I would love to save 15lbs. What about going to a cv front driveline instead of aligning the motor? Could you eliminate the center support bearing then?

Thanks for the info.

When I move my suspension up to down it goes from just feeling the CV start to barely colide inside as I rotate the axel at the top and at the bottom. I have not had any problems but I am right at the limits. I did not balance the driveshaft and could not tell any differance. Our dirveshafts turn about 1/2 the RPMs a standard cars might. Besides a nice piece of DOM tubing is already real true and naturally closely balanced. Yes you could adapt a CV joint to each end but you would have to attach the cut off spleens from your existing U-joints to hook up or find other simular spleens to use. You will get your max turn ability if your front axels come straight out to the side and perpendicular to the front to rear line of the vehicle which they are not in stock layout. Saving 15 pounds is like close to the equivalant to 1 extra HP gained. It's not that hard to shave 180 pounds off the Trooper and that would be real close to 10 extra HP, give or take.

Lenny

2scoops · March 11, 2011

When I move my suspension up to down it goes from just feeling the CV start to barely colide inside as I rotate the axel at the top and at the bottom. I have not had any problems but I am right at the limits. I did not balance the driveshaft and could not tell any differance. Our dirveshafts turn about 1/2 the RPMs a standard cars might. Besides a nice piece of DOM tubing is already real true and naturally closely balanced. Yes you could adapt a CV joint to each end but you would have to attach the cut off spleens from your existing U-joints to hook up or find other simular spleens to use. You will get your max turn ability if your front axels come straight out to the side and perpendicular to the front to rear line of the vehicle which they are not in stock layout. Saving 15 pounds is like close to the equivalant to 1 extra HP gained. It's not that hard to shave 180 pounds off the Trooper and that would be real close to 10 extra HP, give or take.

Lenny

I would like to save some weight. Maybe a "pinned" weight-saving thread should be started, or has it already? I would like to shave 200lbs, but it seems I only keep adding weight with mods. I think I could save a bunch of weight in the seating area.

2scoops · March 11, 2011

Well, I spent a few hours in the garage again. Lowered the front diff to the maximum I felt comfortable. The drain plug is roughly 1/2 inch below the frame (custom skidplate coming). This is probably about 3/4 to 1 inch below stock. And in the end...I gained 1 inch of droop in the suspension. I thought I could gain more. Measuring from eye to eye, taken from them middle of the hole, on the shock mounts my distance is just over 21 inches. Any more than that and the CV's begin to bind. In the end I moved the front diff about 1/2 inch forward. The drive shaft splines are 3 and 3/4 inches long. I have about 2 and 1/4 inch of splines still engaged, so I am comfortable with that. I played around, moving the diff forward as much as 2-3 inches from stock setting, with no noticeable gain in droop. I cut out the tube that the diff originally bolted in order to do so. I replaced it with 1/4 inch steel plate & reused the original mounting bracket.

Now I have to tackle the upper shock mounts.

Lenny · March 11, 2011

I would like to save some weight. Maybe a "pinned" weight-saving thread should be started, or has it already? I would like to shave 200lbs, but it seems I only keep adding weight with mods. I think I could save a bunch of weight in the seating area.

Replacing the steel plates that the seats bolt onto to aluminum can save another 4-5 pounds. It just keeps adding up. I think your idea of a weight saving pinned thread is good.

Lenny