4th gen vs 5th gen rear axle. ZF 9.25 is a inadequate axle assembly for this truck.

[RamMan381]

I have had countless failures of the gear set and limited slip in my 2016 Ram 1500 hemi.

The first failures I can’t blame ram for but we’re related to after market parts and me being semi abusive to the truck.

I gave up on the aftermarket parts and installed a factory zf 9.25, with factory gears “3.92”, and a factory limited slip as assembled by Ram.

Everything was going fine for 2 years but then the last time I towed it started making noise again…. I was not abusive to it during those 2 years out of fear of another failure but here we go again. I have not pulled the cover but I have a mag hytec diff cover so I pulled the magnetic dip stick and it’s got lots of metal flakes on it.

Basically I need to upgrade this axle or sell the truck. Ram has the smallest axle of all the 1/2 ton trucks, it’s inadequate for what I do. I have 35” tires, and a custom tune with catted headers and a muffler. I tow a travel trailer with a 5,500 pound dry weight.

The fact that ram offers the Max Tow option and basically the only upgrade it offers is a properly sized rear axle similar to what ford and Chevy already have installed in their trucks tells me they are aware this zf9.25 is at its limit.

I am desperate, I love my truck, I just can’t keep putting thousands of dollars into the rear end. I’m willing to purchase a brand new super 60 from RAM if I can find one, if it will bolt under my truck.

If I can’t upgrade the rear axle, I need to move on.

 

[DILLIGAF]

Guys are pushing insane amount of power thru these diffs, You know what they dont use is that POS factory LSD

Get a TrueTrac and for the love of god dont go to a stealersh!t to get it install.

 

[Jim BB]

I Put trueTrac in to GMC 3500 Duramax Tow Trucks because they kept blowing the rear gear set out of them ! once i put the TrueTrac in never had another problem those rear gear sets are bullet proof almost ! as long as you put it in as recommended and shimmed properly with good gear oil as recommended !

 

[RamMan381]

Although I have had issues with aftermarket limited slips, I am having problems with the ring and pinion failing.

I understand people can make these hold up decently well on a drag strip, that is much different than towing up mountain passes.

The failures are not related to strength, they are related to heat.

 

[zrock]

i would say the shop that you had do the work is at fault and never assembled the diff properly or to spec. If the ring and pinion is failing then they did not have them meshed properly.. That has nothing to do with strength or heat it would only be a matter of time before it failed..

 

[DILLIGAF]

I am having problems with the ring and pinion failing.

Thats because you got a ******* to install it. Pinions dont fail on these trucks. Its not even a thing.

 

[crazykid1994]

I towed my fathers boat. Boat and trailer combined are 9300lbs. Factory lsd 3.92 gear set. No issues. Lifted on 35s. Long tube headers, full catback exhaust, 6.4 intake manifold, and tuned. Truck did not miss a beat. I don’t drive my truck very nicely either. It gets full throttle quite often and goes off-road. I’ve opened the rear and replaced the diff fluid once. Otherwise it’s never been touched. Factory diff cover with just a diff guard on it for off-road.

 

[Wild one]

I have had countless failures of the gear set and limited slip in my 2016 Ram 1500 hemi.

The first failures I can’t blame ram for but we’re related to after market parts and me being semi abusive to the truck.

I gave up on the aftermarket parts and installed a factory zf 9.25, with factory gears “3.92”, and a factory limited slip as assembled by Ram.

Everything was going fine for 2 years but then the last time I towed it started making noise again…. I was not abusive to it during those 2 years out of fear of another failure but here we go again. I have not pulled the cover but I have a mag hytec diff cover so I pulled the magnetic dip stick and it’s got lots of metal flakes on it.

Basically I need to upgrade this axle or sell the truck. Ram has the smallest axle of all the 1/2 ton trucks, it’s inadequate for what I do. I have 35” tires, and a custom tune with catted headers and a muffler. I tow a travel trailer with a 5,500 pound dry weight.

The fact that ram offers the Max Tow option and basically the only upgrade it offers is a properly sized rear axle similar to what ford and Chevy already have installed in their trucks tells me they are aware this zf9.25 is at its limit.

I am desperate, I love my truck, I just can’t keep putting thousands of dollars into the rear end. I’m willing to purchase a brand new super 60 from RAM if I can find one, if it will bolt under my truck.

If I can’t upgrade the rear axle, I need to move on.

Throw that POS Magtec cover away and re-install the factory cover and put a Tru Trac in it. I'll lay odds alot of your issues are due to the rear end cover not supplying enough fluid to the pinion bearings,causing them to run hot

 

[Jeepwalker]

The stock cover is an integral component which is often overlooked. It's engineered to allow the lube to get (properly) thrown up over the top to the front pinion. Banks did video comparisons of aftermarket diff covers to show that many don't flow fluid very well. They look cool, but some performed terribly. Stock covers pretty much all flowed among the best. But they didn't have the cooling component of course. IDK how yours compared. It's available on youtube.

And maybe some of your failures you had the oem cover installed, IDK ...I'm just adding to what Wild One suggested above, FWIW.

 

[RamMan381]

Does anyone know if a 5th gen axle will bolt in and work on a 4th gen truck! I am at the point we’re I will purchase one directly from RAM if I can make this work. Only other options are selling the truck or having custom brackets welded to a aftermarket Dana 60.

I am embarrassed but here is the list of parts.

These parts were installed by the most trusted gear installer in Oregon. I have had many Jeeps and he has done gears and lockers in all of them. He is a perfectionist, people in the industry trust and respect him.

#1. Yukon 3.90 gears and auburn limited slip. Gears failed not long after install due to heat. Covered by gear installer warranty.

#2 Yukon 3.90 gears with same limited slip. Gears failed not long after due to heat again….. Gear installer covered half the repair cost and I covered the other half.

#3 Nitro 3.92 gears “REM polished at weddleindustries”, the same auburn limited slip. Auburn failed after stepping on the gas hard from a stop. Parts went through the gears and messed everything up. I was hard on it but the failure should not have happened and now it’s known that the auburn units are weak in the zf 9.25 rear end.

#4. Nitro 3.92 gears, Yukon guragrip. I believe this was mostly my fault. Having fun, got on the gas from a stop to drift a turn. I got wheel hop and broke a spider gear which then proceeded to destroy the gears. It’s now known the duragrip limited slips are known to break spider gears when abused. I covered repair costs myself.

#5 New factory axle assembly. I bought another stock axle complete with factory 3.92 gears, and factory limited slip. I did not have a dealership setup the gears, is a factory assembled axle. I stopped being so abusive on the truck as well. Towing my travel trailer and dirt bike home from the moto track I started hearing some noise I was not hearing previously. I assumed the gears were failing from the metal I see on the magnetic dipstick. This is where I am today.

I bought this truck new in 2016, it has been absolutely flawless except for the rear axle.

It has been a learning curve.

Yukon 3.90 gears are absolute trash for the ZF 9.25 specifically in the 3.90 ratio. There is not enough teeth on the pinion and if used in a towing situation it will fail. There is a difference between a 3.90 and a 3.92 gear set. This is why my nitro gears and factory gears held up substantially longer than the **** Yukon 3.90 gears. “ZF & Nitro are both 3.92 and have more teeth on the pinion gear”

Previously the trutrac was not available and Auburn was the only one making aftermarket limited slips. The auburns are weak and will not last when abused.

Then the duragrip came out, it’s better than the auburn but the spider gears are known to fail.

Now we have the trutrac. The only downside is they specify 80w90 which is unacceptable for the load towing puts on the gears and will cause the gears to burn up.

I am going to have 3.92 AAM gears REM polished and installed with a trutrac using synthetic 75w-140. I am considering this a band aid and will either sell the truck or find another axle that will hold up.

The super 60 installed in the rams with the max tow option seems like the ticket.

 

[RamMan381]

Throw that POS Magtec cover away and re-install the factory cover and put a Tru Trac in it. I'll lay odds alot of your issues are due to the rear end cover not supplying enough fluid to the pinion bearings,causing them to run hot

I have never had a problem with pinion bearings.

 

[RamMan381]

The stock cover is an integral component which is often overlooked. It's engineered to allow the lube to get (properly) thrown up over the top to the front pinion. Banks did video comparisons of aftermarket diff covers to show that many don't flow fluid very well. They look cool, but some performed terribly. Stock covers pretty much all flowed among the best. But they didn't have the cooling component of course. IDK how yours compared. It's available on youtube.

And maybe some of your failures you had the oem cover installed, IDK ...I'm just adding to what Wild One suggested above, FWIW.

Initially I had the factory cover installed but installed the aftermarket cover so I could easily check the condition of the oil and see if there was metal shavings on the dipstick.

I have seen the videos and partially agree with what he is saying. I have yet to see any evidence of aftermarket diff covers actually causing failure. Maybe I am the unfortunate evidence though.

But I will install the factory cover this go around.

 

[RamMan381]

I towed my fathers boat. Boat and trailer combined are 9300lbs. Factory lsd 3.92 gear set. No issues. Lifted on 35s. Long tube headers, full catback exhaust, 6.4 intake manifold, and tuned. Truck did not miss a beat. I don’t drive my truck very nicely either. It gets full throttle quite often and goes off-road. I’ve opened the rear and replaced the diff fluid once. Otherwise it’s never been touched. Factory diff cover with just a diff guard on it for off-road.

I towed my fathers boat. Boat and trailer combined are 9300lbs. Factory lsd 3.92 gear set. No issues. Lifted on 35s. Long tube headers, full catback exhaust, 6.4 intake manifold, and tuned. Truck did not miss a beat. I don’t drive my truck very nicely either. It gets full throttle quite often and goes off-road. I’ve opened the rear and replaced the diff fluid once. Otherwise it’s never been touched. Factory diff cover with just a diff guard on it for off-road.

You do not tow often, I tow very frequently and over mountain passes. How often do you tow that boat?

 

[Jeepwalker]

Its really hard to say on your rear diff. There are factors which nobody can know: quality of materials, quality of install & other factors. I haven't really read of problems on this forum, but I certainly don't doubt your (unfortunate) experience. I would be extremely frustrated too

 

[crazykid1994]

You do not tow often, I tow very frequently and over mountain passes. How often do you tow that boat?

I may not tow the boat often but I do haul a few hundred pounds around in the bed at all times for off-roading. Granted the truck only has 46,000 miles on it. I’ve hauled lumber and concrete on numerous occasions weighing near 1000lbs. To answer the 4th gen to 5th gen question. No. It’s not a direct swap. The axle may bolt in but you will run into a few other issues. Primarily being the emergency brake is electronic on the 5th gen and the axle is 6 lug not your 5 lug. There is a member on this forum who hotshots his truck. He has a 4th gen ecodiesel and I believe made over half a million miles on his truck last time I checked.

 

[RamMan381]

I may not tow the boat often but I do haul a few hundred pounds around in the bed at all times for off-roading. Granted the truck only has 46,000 miles on it. I’ve hauled lumber and concrete on numerous occasions weighing near 1000lbs. To answer the 4th gen to 5th gen question. No. It’s not a direct swap. The axle may bolt in but you will run into a few other issues. Primarily being the emergency brake is electronic on the 5th gen and the axle is 6 lug not your 5 lug. There is a member on this forum who hotshots his truck. He has a 4th gen ecodiesel and I believe made over half a million miles on his truck last time I checked.

Thank you for this information, having not seen one of these 5th gens upclose I was not aware of those changes. Maybe the backing plates would swap over with the brake hardware but being a completely different axle manufacturer I find this doubtful.

But as far as you know the control arms, trackbar, swaybar, and spring mounts are all the same?

 

[Wild one]

Does anyone know if a 5th gen axle will bolt in and work on a 4th gen truck! I am at the point we’re I will purchase one directly from RAM if I can make this work. Only other options are selling the truck or having custom brackets welded to a aftermarket Dana 60.

I am embarrassed but here is the list of parts.

These parts were installed by the most trusted gear installer in Oregon. I have had many Jeeps and he has done gears and lockers in all of them. He is a perfectionist, people in the industry trust and respect him.

#1. Yukon 3.90 gears and auburn limited slip. Gears failed not long after install due to heat. Covered by gear installer warranty.

#2 Yukon 3.90 gears with same limited slip. Gears failed not long after due to heat again….. Gear installer covered half the repair cost and I covered the other half.

#3 Nitro 3.92 gears “REM polished at weddleindustries”, the same auburn limited slip. Auburn failed after stepping on the gas hard from a stop. Parts went through the gears and messed everything up. I was hard on it but the failure should not have happened and now it’s known that the auburn units are weak in the zf 9.25 rear end.

#4. Nitro 3.92 gears, Yukon guragrip. I believe this was mostly my fault. Having fun, got on the gas from a stop to drift a turn. I got wheel hop and broke a spider gear which then proceeded to destroy the gears. It’s now known the duragrip limited slips are known to break spider gears when abused. I covered repair costs myself.

#5 New factory axle assembly. I bought another stock axle complete with factory 3.92 gears, and factory limited slip. I did not have a dealership setup the gears, is a factory assembled axle. I stopped being so abusive on the truck as well. Towing my travel trailer and dirt bike home from the moto track I started hearing some noise I was not hearing previously. I assumed the gears were failing from the metal I see on the magnetic dipstick. This is where I am today.

I bought this truck new in 2016, it has been absolutely flawless except for the rear axle.

It has been a learning curve.

Yukon 3.90 gears are absolute trash for the ZF 9.25 specifically in the 3.90 ratio. There is not enough teeth on the pinion and if used in a towing situation it will fail. There is a difference between a 3.90 and a 3.92 gear set. This is why my nitro gears and factory gears held up substantially longer than the **** Yukon 3.90 gears. “ZF & Nitro are both 3.92 and have more teeth on the pinion gear”

Previously the trutrac was not available and Auburn was the only one making aftermarket limited slips. The auburns are weak and will not last when abused.

Then the duragrip came out, it’s better than the auburn but the spider gears are known to fail.

Now we have the trutrac. The only downside is they specify 80w90 which is unacceptable for the load towing puts on the gears and will cause the gears to burn up.

I am going to have 3.92 AAM gears REM polished and installed with a trutrac using synthetic 75w-140. I am considering this a band aid and will either sell the truck or find another axle that will hold up.

The super 60 installed in the rams with the max tow option seems like the ticket.

I have the earlier AAM Tru Trac in my ZF diff,the one where you had to buy the extra axle to make work,and it calls for 75W-140,i'm not sure why they went to a 80W-90,but i'd go back to a 140 spec lube in the later tru trac assembly.
They do reconmend a mineral lube do to the slipperness factor of synthetic,but they also say a high quality synthenic lube can be used
The common denometer in your failures appears to be the MagTec cover,and i'd hazard a guess,it's not supplying enough lube to the pinion / pinoin bearings and ring gear,as we can rule out installer error if you bought a completely new housing

 

[TotallyHucked]

Damn. I don't have anything of significance to offer but you've got some crazy bad luck going on with that truck. My buddy has a '13 with 200k+ miles and has only replaced a failed/noisy pinion bearing and fluid replacement, no other issues and it spent 75% of it's life towing. My dad's '14 has 165k with no rear end issues and my '17 has 78k with no issues. I honestly would have someone inspect the current gearset before making any big purchases. It may be a bad pinion bearing, you might get away with that repair, the stock cover and fresh fluid and be fine for a long time.

 

[RamMan381]

Damn. I don't have anything of significance to offer but you've got some crazy bad luck going on with that truck. My buddy has a '13 with 200k+ miles and has only replaced a failed/noisy pinion bearing and fluid replacement, no other issues and it spent 75% of its life towing. My dad's '14 has 165k with no rear end issues and my '17 has 78k with no issues. I honestly would have someone inspect the current gearset before making any big purchases. It may be a bad pinion bearing, you might get away with that repair, the stock cover and fresh fluid and be fine for a long time.

I have the original axle assembly so it will be the one getting new parts installed. When I swap axles I will disassemble and inspect what failed. Hopefully it’s just the pinion bearing but I doubt I would get that lucky.

I’m hoping you guys are right and the diff cover is the issue. Although I searched and can not find any evidence of failures caused by aftermarket differential covers. Just marketing by Gale Banks, which he is exceptionally good at and sells an extremely more expensive product than everyone else.

 

[caulk04]

Aftermarket diff covers look cool, that's all. 'Ease of service', meh. The time spent servicing that item vs time spent driving is so miniscule.