Hummer H3 HD Dana 50/ CV shaft upgrade

[atvspeed4]

Have not been able to figure it out. Same vehicle, same bushings, same housing, same part number cv shafts. Really frustrating we have crate of 5 housings and custom machined shafts just sitting collecting dust. One of our friends is running one in his H3 to log miles and trail time to see if he has same failure mode.

 

[EndeavoredH3]

Have not been able to figure it out. Same vehicle, same bushings, same housing, same part number cv shafts. Really frustrating we have crate of 5 housings and custom machined shafts just sitting collecting dust. One of our friends is running one in his H3 to log miles and trail time to see if he has same failure mode.

I’d be more than glad to test it out west .

In all seriousness, can log miles all over Arizona. Have rock trails 30 minutes away, and can daily drive ~30 miles a day if needed. Have experience with aftermarket one off parts, understand nothing aftermarket is a one size fits all and can adapt the differential as needed.

 

[atvspeed4]

I’d be more than glad to test it out west .

In all seriousness, can log miles all over Arizona. Have rock trails 30 minutes away, and can daily drive ~30 miles a day if needed. Have experience with aftermarket one off parts, understand nothing aftermarket is a one size fits all and can adapt the differential as needed.

If you were closer we could consider it but we really want to be local so if there are any issues we can get our eyes on it quick, pull it apart, troubleshoot and get it back on the trail.

 

[EndeavoredH3]

If you were closer we could consider it but we really want to be local so if there are any issues we can get our eyes on it quick, pull it apart, troubleshoot and get it back on the trail.

As much as Id like to have this differential under the truck, I equally understand you guys wanting to keep it local.

 

[rascole]

As much as Id like to have this differential under the truck, I equally understand you guys wanting to keep it local.

Sounds like a driveway swap is needed in Sand Hollow this year!!!!!

 

[EndeavoredH3]

Sounds like a driveway swap is needed in Sand Hollow this year!!!!!

There could be free shipping on Sand Hallow parts express…

 

[atvspeed4]

Our best guess right now on the issue of the CVs is that of the four H3s that have run the diff, the three that did not have a problem were running our prototype billet aluminum sleeve/ UHMW carbon black lower control arm bushings. The truck we had at the vermont pilgrimage overland event in the fall was completely stock other than the diff/ cvs and the lower control arm bushings were very old. The stock lower control arm bushings on an H3 are so large that they allow around 3/8" movement of the control arm on each side of the truck in all directions under load. This would be enough to cause the CV to hit the cross support of the lower control arm or pull out of the inner tripod cup.

 

[Ridinhigh1500]

Our best guess right now on the issue of the CVs is that of the four H3s that have run the diff, the three that did not have a problem were running our prototype billet aluminum sleeve/ UHMW carbon black lower control arm bushings. The truck we had at the vermont pilgrimage overland event in the fall was completely stock other than the diff/ cvs and the lower control arm bushings were very old. The stock lower control arm bushings on an H3 are so large that they allow around 3/8" movement of the control arm on each side of the truck in all directions under load. This would be enough to cause the CV to hit the cross support of the lower control arm or pull out of the inner tripod cup.

You guys doing any southeast events? I'm in coastal NC, would love to see this in person.

 

[atvspeed4]

You guys doing any southeast events? I'm in coastal NC, would love to see this in person.

Sorry we are not this year. Just sold our company H3 to a good friend of ours that has been testing the Dana 50 so we will need to build the next truck before we head out on a trip.

 

[atvspeed4]

Figured we would keep Chris' thread organized and bring discussion back here. The two issues outstanding: 1.) The larger plunging cv we tried at full droop makes contact with the lower control arm cross piece. 2.) Worn OEM lower control arm bushings allow 1/2" each side of track width change which can pull out the regular CVs we have used for years. The only trucks that have not had this issue are the ones running our crazy expensive to make lower control arm bushings.

 

[cgalpha08]

Figured we would keep Chris' thread organized and bring discussion back here. The two issues outstanding: 1.) The larger plunging cv we tried at full droop makes contact with the lower control arm cross piece. 2.) Worn OEM lower control arm bushings allow 1/2" each side of track width change which can pull out the regular CVs we have used for years. The only trucks that have not had this issue are the ones running our crazy expensive to make lower control arm bushings.

For droop, you could put a limit strap in, or clearance the control arm with a grinder for the small bit that contacts it.

What bushing material are the lowers made out of?

 

[atvspeed4]

The outer sleeve is machined out of solid 6061 bar stock, bushing is UV stable UHMW carbon black and the center crush sleeve is DOM. We have been running the same set in a couple trucks since 2017 through new england weather and constant wheeling without any play developing.

 

[H3TONKA]

Hey guys. Just thought I'd chime in again and say how keen I am to see you get this project perfected & on the market for us H3 enthusiasts to fit onto our rigs.
Been following this thread very closely and have been doing some mods on my own H3 as you've been pointing out the problems you've encountered. One of which is the control arm bushing movement causing the cv shaft to hit the bottom control arm cross piece.
I have installed a full set of polyurethane bushes on my H3 from Siberianbushings.com that I've now logged alot of miles on. Recently we were able to borrow a machine we call a Suspension Shaker which is a heavy duty shaking machine used to test Suspension/steering components on prime movers. Doing a side by side test with my H3 with the Polyurethane bushes & a H3 with standard rubber bushes we found that polyurethane bushes had very little flexibility in all tests, but the rubber bushed H3 had up to 1/2inch of movement especially at the full droop when the shock got to full extension it pulled the lower control arm into an upwards position at the crosspeice section. How ever the polyurethane bushed H3 did not show this movement at all. The Siberianbushings.com are off the shelf product and readily available, so far they have held up very strong and a much better ride with no signs of fatigue after 2 years of wheeling. Not sure if this helps at all but thought it was worth sharing & might be an alternative to you guys making custom bushes at a large expense.
Still super keen to get my hands on one of these conversions once available.

 

[atvspeed4]

Hey guys. Just thought I'd chime in again and say how keen I am to see you get this project perfected & on the market for us H3 enthusiasts to fit onto our rigs.
Been following this thread very closely and have been doing some mods on my own H3 as you've been pointing out the problems you've encountered. One of which is the control arm bushing movement causing the cv shaft to hit the bottom control arm cross piece.
I have installed a full set of polyurethane bushes on my H3 from Siberianbushings.com that I've now logged alot of miles on. Recently we were able to borrow a machine we call a Suspension Shaker which is a heavy duty shaking machine used to test Suspension/steering components on prime movers. Doing a side by side test with my H3 with the Polyurethane bushes & a H3 with standard rubber bushes we found that polyurethane bushes had very little flexibility in all tests, but the rubber bushed H3 had up to 1/2inch of movement especially at the full droop when the shock got to full extension it pulled the lower control arm into an upwards position at the crosspeice section. How ever the polyurethane bushed H3 did not show this movement at all. The Siberianbushings.com are off the shelf product and readily available, so far they have held up very strong and a much better ride with no signs of fatigue after 2 years of wheeling. Not sure if this helps at all but thought it was worth sharing & might be an alternative to you guys making custom bushes at a large expense.
Still super keen to get my hands on one of these conversions once available.

Our friend that bought one of our H3 with the prototype air locked diff has already had the siberian bushings fail. We originally made parts for the S10 platform and we all used to run poly bushings but they failed pretty quick with the salt and constant wheeling. Im glad to hear you are having good luck with them but we have not unfortunately

 

[H3TONKA]

Our friend that bought one of our H3 with the prototype air locked diff has already had the siberian bushings fail. We originally made parts for the S10 platform and we all used to run poly bushings but they failed pretty quick with the salt and constant wheeling. Im glad to hear you are having good luck with them but we have not unfortunately

Sorry to hear youve had no success with these bushes but that is good to know what their life span expectancy is, cheers for the feedback.
I've had a good run with my bushes so far but we live in a very dry climate here in Central Australia so my rig has never seen salt, I read alot about you guys and the battles with salt. Admittedly I do not do any hard offroad work either just daily driving on sealed roads and dirt tracks with a bit of mud occasionally if it rains, which is not often. Mind you our roads here in Oz are getting fairly rough so the suspension does get a fair workout but nothing like you'd be putting your rigs through doing hardcore wheeling on the weekends. We only ran some tests on the shaker machine because we had it on loan to service our heavy haulage trucks & thought we may have a solution for you.
I'm mainly interested in the diff conversion to play with gear ratios and added strength to support 500hp that im pushing through the drive train.It would be awsome to keep the IFS rather than solid axle swap, not a big fan of that idea.
I already have most of the mods you guys offer on my h3 and they are rock solid parts and follow your advice on other repairs too like the tailgate striker plate fix. Big fan of your work and knowledge.

 

[atvspeed4]

Sorry to hear youve had no success with these bushes but that is good to know what their life span expectancy is, cheers for the feedback.
I've had a good run with my bushes so far but we live in a very dry climate here in Central Australia so my rig has never seen salt, I read alot about you guys and the battles with salt. Admittedly I do not do any hard offroad work either just daily driving on sealed roads and dirt tracks with a bit of mud occasionally if it rains, which is not often. Mind you our roads here in Oz are getting fairly rough so the suspension does get a fair workout but nothing like you'd be putting your rigs through doing hardcore wheeling on the weekends. We only ran some tests on the shaker machine because we had it on loan to service our heavy haulage trucks & thought we may have a solution for you.
I'm mainly interested in the diff conversion to play with gear ratios and added strength to support 500hp that im pushing through the drive train.It would be awsome to keep the IFS rather than solid axle swap, not a big fan of that idea.
I already have most of the mods you guys offer on my h3 and they are rock solid parts and follow your advice on other repairs too like the tailgate striker plate fix. Big fan of your work and knowledge.

Thank you! Really hoping we can figure this all out. The gear driven trutrac limited slip dana 50 we have been running would be awesome with high horsepower builds. Makes the launch so much more predictable and prevents the side to side darting you get with AWD and open diff. We always wanted to build a LSX 454 swapped H3 with truetracs front and rear with linked suspension in the back.

 

[H3TONKA]

Thank you! Really hoping we can figure this all out. The gear driven trutrac limited slip dana 50 we have been running would be awesome with high horsepower builds. Makes the launch so much more predictable and prevents the side to side darting you get with AWD and open diff. We always wanted to build a LSX 454 swapped H3 with truetracs front and rear with linked suspension in the back.

Yes the open front diff is lethal on launch with that side step out. A limited slip on the dana50 would definitely be a dream come true. Linked rear would be amazing, if you ever made that work I'd be keen to do the same for sure. Have you guys ever seen it done on a h3?
LSX 454 h3 with both diffs done and linked rear.... now that would be a tough build, how much fun would that be to drive

 

[atvspeed4]

The motor would fit fine as its the same block as the 5.3 etc just need to switch to truck accessories or play with the aftermarket options for moving a few things on accessory drive. A bunch of people have linked the rear but not alot have done it at stock height from what I have seen. Its definitely tricky with gas tank clearance but should be doable. The biggest issue with the h3 platform we found in Moab wheeling really hard was the upper control arm mounts shearing off the alignment pins. We ended up having to buy a bag of them and keep pressing them in a couple times a day. We were running prototype upper control arms that had our carbon black UHMW bushings so not alot of give with those. We had started on a set of a-arms back in 2012 that deleted the alignment pins and went to rebuildable joints but have been focused on the diff project since.

 

[H3TONKA]

The motor would fit fine as its the same block as the 5.3 etc just need to switch to truck accessories or play with the aftermarket options for moving a few things on accessory drive. A bunch of people have linked the rear but not alot have done it at stock height from what I have seen. Its definitely tricky with gas tank clearance but should be doable. The biggest issue with the h3 platform we found in Moab wheeling really hard was the upper control arm mounts shearing off the alignment pins. We ended up having to buy a bag of them and keep pressing them in a couple times a day. We were running prototype upper control arms that had our carbon black UHMW bushings so not alot of give with those. We had started on a set of a-arms back in 2012 that deleted the alignment pins and went to rebuildable joints but have been focused on the diff project since.

Wow you guys have really done alot of development, testing and breaking things on these rigs over the years, it's very cool. Sounds like you definitely put your vehicles through their absolute maximum limits while out wheeling, would be alot of fun.
Always wondered if anyone had tried custom front control arms for better geometry and adjustment on the H3. I looked into linking the rear end myself but over here in Australia custom fab shops that could do work like that are very hard to find and the cost is so high for the average driver it's only available for the filthy rich and even then you'd be lucky to get it done. So us average Joe's really depend on guys such as yourselves to develop these mods into kit form so we can import into our country and DIY ourselves. The most focus over here are vehicles like Toyota landcruisers, ford Rangers etc which have an endless supply of locally developed mods available. Such a shame the H3 didn't go any further than it did on the market, would've been some cool ideas available for them by now.
So glad to hear you are still focusing on getting the Dana50 project to work , it's obviously been a very tricky job to get running perfectly and there's probably a heap of us that have alot of faith that you will succeed. It kind of almost the missing link for my H3 that would make my rig drive perfectly for my needs and one of the last mods I'd like to do performance wise. Would almost sell a vital organ to get my hands on one just for it's strength and gear ratio options. Will definitely be amongst the first to grab one for sure.

 

[rascole]

The motor would fit fine as its the same block as the 5.3 etc just need to switch to truck accessories or play with the aftermarket options for moving a few things on accessory drive. A bunch of people have linked the rear but not alot have done it at stock height from what I have seen. Its definitely tricky with gas tank clearance but should be doable. The biggest issue with the h3 platform we found in Moab wheeling really hard was the upper control arm mounts shearing off the alignment pins. We ended up having to buy a bag of them and keep pressing them in a couple times a day. We were running prototype upper control arms that had our carbon black UHMW bushings so not alot of give with those. We had started on a set of a-arms back in 2012 that deleted the alignment pins and went to rebuildable joints but have been focused on the diff project since.

Have you looked into a cantilever rear? There are a few Toyota builds around here using it. With the resonator removed, it frees up a good amount of room under the rear.

 

[atvspeed4]

Have you looked into a cantilever rear? There are a few Toyota builds around here using it. With the resonator removed, it frees up a good amount of room under the rear.

That would be the ideal setup! We were looking at modifying a kit for Fj cruisers that seemed pretty close but never took the plunge. Really what someone needs to do is make a replacement rolling chassis that people could order. Its becoming common for other brands and with all of the frames rotting and breaking here due to salt and old age.

 

[H3TONKA]

Have you looked into a cantilever rear? There are a few Toyota builds around here using it. With the resonator removed, it frees up a good amount of room under the rear.

A while back when while doing some research on linked rear ends I did come across a write up about a company that did a cantilever set up on a H3 using coilovers tucked up sideways behind the fuel tank above the rear diff. It was for a 4inch lift if I recall and they had totally changed the exhaust system to make it possible. Would be awsome to see some of these kind of kits become available on the market without the use of one off expensive custom fab shop jobs.