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Hummer H3 HD Dana 50/ CV shaft upgrade

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Just pulled both of our test front diffs that have about 4 years on them now to take apart for inspection. Trying to sort out axle seal leaks that we have been having for a little while now. Was a slow drip but has gotten worse over past year.
 

H3TONKA

Member
Messages
7
Location
Australia
Just pulled both of our test front diffs that have about 4 years on them now to take apart for inspection. Trying to sort out axle seal leaks that we have been having for a little while now. Was a slow drip but has gotten worse over past year.
Hey guys. Just wondering if there has been any further updates on your progress so far. Super keen to get my hands on one of these if they become available.
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Axle seal issue appears to have been fixed on final version of seals. We have been logging miles on this final version and just put in order for run of bushings for the production version. Getting close... Next month we are pulling diff, checking for leaks, fluid condition, bearings, wear pattern etc
 

H3TONKA

Member
Messages
7
Location
Australia
Just pulled both of our test front diffs that have about 4 years on them now to take apart for inspection. Trying to sort out axle seal leaks that we have been having for a little while now. Was a slow drip but has gotten worse over past year.
Hey guys. Just wondering if there has been any further updates on your progress so far. Super keen to get my hands on one of these if they become available.
 

H3TONKA

Member
Messages
7
Location
Australia
Some how I've managed to post the same thing twice sorry about that.
This is exciting news, sounds like your getting close to perfecting your design now, eager to find out more info as you get closer. Will definitely be ordering a unit when they are available.
 

EndeavoredH3

Well-Known Member
Messages
371
Location
Arizona
Axle seal issue appears to have been fixed on final version of seals. We have been logging miles on this final version and just put in order for run of bushings for the production version. Getting close... Next month we are pulling diff, checking for leaks, fluid condition, bearings, wear pattern etc
CB9D371F-3276-4CC1-B7DE-38E4EDEB484D.jpeg
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Still kicking. Dropped the truck off 3 weeks ago to see why seals were leaking AGAIN. They said it appears diff was overfilled despite following their new fill level so they are going to adjust level again and we will test it out. This is going to be frustrating as we know there will be people that overfill and then complain that seals are leaking on this very expensive product. Hopefully call goes well with them tomorrow and we can get it back to our shop Friday to start logging more miles. We also have new telescoping CVs we want to test to see if they clear the lower control arm and shocks. If they do this would be an awesome upgrade. (We still haven't broken the cvs we have been running for the past 8 years on 37s but anything is possible in Moab)
 

H3TONKA

Member
Messages
7
Location
Australia
Still kicking. Dropped the truck off 3 weeks ago to see why seals were leaking AGAIN. They said it appears diff was overfilled despite following their new fill level so they are going to adjust level again and we will test it out. This is going to be frustrating as we know there will be people that overfill and then complain that seals are leaking on this very expensive product. Hopefully call goes well with them tomorrow and we can get it back to our shop Friday to start logging more miles. We also have new telescoping CVs we want to test to see if they clear the lower control arm and shocks. If they do this would be an awesome upgrade. (We still haven't broken the cvs we have been running for the past 8 years on 37s but anything is possible in Moab)
Still super keen to get one. Hopefully you'll get to the perfect results sometime in the near future. Seems there's a few of us that want this swap now. Keep up the good work guys!
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Good news, they think it wasn't a huge issue. It appears that since this specific one has been our prototype housing for near 8 years and been pressed apart/ pressed together so many times testing different combinations that there was a tolerance issue that caused the slow leak. They rebuilt the diff which is the trutrac version hopefully for the last time and should be throwing back in our company test mule end of this week.
 

H3TONKA

Member
Messages
7
Location
Australia
Good news, they think it wasn't a huge issue. It appears that since this specific one has been our prototype housing for near 8 years and been pressed apart/ pressed together so many times testing different combinations that there was a tolerance issue that caused the slow leak. They rebuilt the diff which is the trutrac version hopefully for the last time and should be throwing back in our company test mule end of this week.
Best of luck with this next test run, hopefully it's the last one. We all have our fingers crossed that you guys have finally nailed it. Great job for sticking to it & keeping us updated with this project.
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Well little delay as our HD driveshaft we did not grease the slip joint so it rusted solid totally our fault and was not able to be reinstalled when they put the dana 50 back in. We are officially back on the road and logging miles now.
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Well it was finally a success! No leaks and the new HD plunging CVs fit. At full lock and full compression with the bump stop slammed all the way into the cup the inner rubber boot barely touches the control arm but it won't cause any issues. Our old cvs with the tripod joint and larger boot rubbed often at just below ride height and we never had a boot fail in 8 years so we are not concerned with this ever so slight contact in extreme conditions.

We are waiting for a run of bushings and updated pricing from all of our vendors to finally list the first five for sale.
 

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rascole

Well-Known Member
Messages
2,580
Location
Bellflower, CA
Hell yeah. Great news. Now to test them in Sand Hollow in a couple of weeks right? I am curious about the CV's and their performance, do you expect a significant strength increase over stock?
 

alrock

El Diablo
Staff member
Messages
10,442
Location
Scottsdale
Hell yeah. Great news. Now to test them in Sand Hollow in a couple of weeks right? I am curious about the CV's and their performance, do you expect a significant strength increase over stock?
I agree. It ain't tested until it's run with the Black Sheep!

Nonetheless, glad to hear the great news.
 

atvspeed4

Well-Known Member
Messages
1,173
Location
massachusetts
Hell yeah. Great news. Now to test them in Sand Hollow in a couple of weeks right? I am curious about the CV's and their performance, do you expect a significant strength increase over stock?

The only failures we have had over the years were the inner tripod style joint cracking the outer housing when fully extended. This removes the tripod and replaces with rzeppa joint like the outer cv and utilizes slip splines with ball bearings. Should be good improvement and they are cheap on rockauto now. The only downside is that with how tightly packaged everything is this is really the only CV shaft than can be run but for $144 each keep two spares if you want.

We'd love to get out for a run but short for time this year with a few massive projects we are on for our full time jobs. Hopefully next year we can get out for a group run
 

EndeavoredH3

Well-Known Member
Messages
371
Location
Arizona
The only failures we have had over the years were the inner tripod style joint cracking the outer housing when fully extended. This removes the tripod and replaces with rzeppa joint like the outer cv and utilizes slip splines with ball bearings. Should be good improvement and they are cheap on rockauto now. The only downside is that with how tightly packaged everything is this is really the only CV shaft than can be run but for $144 each keep two spares if you want.

We'd love to get out for a run but short for time this year with a few massive projects we are on for our full time jobs. Hopefully next year we can get out for a group run
I’ll be in the group run for next year, this years a little tight from bidenomics. Good work, hope we all weren’t too annoying poking around about completion 😁
 

Acer4LO

Well-Known Member
Messages
750
Location
Illinois
This is really incredible news. I am excited! Do you guys have any idea what's the price will be? I have a feeling that this is going to been more expensive than the S10 diff since it is heavier duty, and with the cost of materials.
 
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