Front axles not working in 4 wheel drive

[Indyharleyguy]

cucvrus Thanks for the link. Since the passenger side axle was turning when I had the hub locked in when I turned the front drive shaft is there a chance its not bad or does it just need replaced? And if if I replace one side should I replace both at the same time?

 

[cucvrus]

They are sold in sets. 1 pair. I would fix what you have if it is repairable. They are very easy to work on. Clean them and reassemble them. As long as they are not broken fix what you have. Take them apart. Clean the. Lube them. And reinstall. Unless they have broken parts. Then replace them. I have lots of parts for them. But it is hardtop tell what you need from my seat. Happy Holidays.

 

[sneekyeye]

It may be as simple as cleaning out old hardened grease or dirt in there, replacing a bad seal and reassembling. You won't know until you take it apart and look

 

[Recovry4x4]

Dive in there. This guys vid gives you an idea of how they come out. Didn't watch the whole thing.

https://youtu.be/3rQZeV92OD4

 

[Indyharleyguy]

Hi Recovry4x4 Thanks for the video.

 

[Recovry4x4]

Let me add this. I just watched part of the video, there are some less than ideal pointers in it. At least it gets your hub off.

 

[snowtrac nome]

If you find your hub rusty or full of water plan on replacing wheel bearings, and removing the spindles to replace the seal behind it. That's where the water gets in 90 percent of the time. too many mechanics will not completely service the front end and a year later you will be doing it all over again.

 

[snowtrac nome]

This guy does it right. https://www.youtube.com/watch?v=jm0Bx-nmOgM

 

[Indyharleyguy]

Thanks all. Just ordered this and a conversion kit in case i need it? Will be putting it on this Sunday.
https://www.gowarn.com/prodDetail.aspx?partNo=WAR20990

 

[cucvrus]

This is what I found on my neighbors m1028 when he told me the 4WD was not working. Lack of maintenance kills the best of them.

 

[Indyharleyguy]

Hi again. Wanted to give an update then ask another question. Because of the weather in the Indy area I hired someone to replace the right hub. He did and it works well now. But here's my problem now. Right after he replaced it I drove in some snow in 4 WD High and didn't go more than about 45 MPH for about 20 minutes each way. Last week we had ice in our area and and again I was in 4 WD High but was maybe 50 to 55 MPH in some good spots After about 25 minutes we started smelling something weird. I pull over and put it back in 2 WD but left the hubs locked in. It actually kinda shuttered when I took off. When I stopped the 2nd time I unlocked the hubs. Drove about 35 minutes back home. Went back to the mechanic to have him check it. He said the right hub was fine but he felt some shavings in the front Pig. I had him replace the left hub at that time also. My questions are was 55 MPH in 4 WD high to fast? Should I remove all the fluid in the front pig and then inspect it? Last time in 4 WD high I didn't have any problems but not sure of the speed I was driving at.
Thanks for all advice.

 

[wheelspinner]

It's not the "speed" so much. It's operating in mixed dry and slippery conditions (which I'm guessing it was based on going 55?). If it's was all slippery road the whole time, then it was justtime for parts to wear out. You fixed one problem and found the next weak spot.

 

[rustystud]

You never drive on dry roads at any speed with the front axle locked in. The ring gears are different ratios front and rear. This is to keep the vehicle going straight when your in the mud or snow. When it is dry or even wet with good traction your literally pulling the truck apart ! What ends up breaking is the differentials though. When I say differential I mean the whole axle assembly so that includes the hubs. Since the front is usually weaker then the rear it tends to blow out first. Either that or the transfer case goes. Also just a rule of thumb is to never drive over 35 mph when the front axle is engaged.

 

[rsh4364]

I am confused, are you talking about different ring and pinion gears in the front and rear differentials on a cucv?

 

[sandcobra164]

Negative, they are both 4.56 ratio axles. The problem comes in when you think about wheels on a vehicle through a turn. The front wheels tend to turn slightly more revolutions as the rear axle takes the shorter route. Leaving the front axle hub lockers engaged adds stress to the drivetrain on dry pavement or any other good traction surface. In dirt or soft ground, it can easily dissipate it. The shuddering felt by Indyharleyguy was likely caused by the locker in the rear axle on a low traction surface. Mine does it anytime I get on the throttle too hard in my M1028 on my dirt road or when making a turn on pavement.

 

[rodent]

When was the last time you had the oil changed in the front diff? If you had gone through some deep water spots, it can enter through the seals and contaminate the gear oil. I'd pull the front diff cover ASAP to make sure the gears and oil look ok. Any shop should be able to do this.

 

[rustystud]

Negative, they are both 4.56 ratio axles. The problem comes in when you think about wheels on a vehicle through a turn. The front wheels tend to turn slightly more revolutions as the rear axle takes the shorter route. Leaving the front axle hub lockers engaged adds stress to the drivetrain on dry pavement or any other good traction surface. In dirt or soft ground, it can easily dissipate it. The shuddering felt by Indyharleyguy was likely caused by the locker in the rear axle on a low traction surface. Mine does it anytime I get on the throttle too hard in my M1028 on my dirt road or when making a turn on pavement.

Go to "Randy's Ring and Pinion" and look up our application for a M1009 . You will see the front differential has a ratio of 3.08:1 while the rear has 3.07:1 . The M1028 had a ratio of 4.56:1 in the rear. I don't know what the front is though. All 4X4's have this. The only ones that do not are the constant 4X4 units. I rebuilt differentials for decades and this is the norm.

 

[Indyharleyguy]

When was the last time you had the oil changed in the front diff? If you had gone through some deep water spots, it can enter through the seals and contaminate the gear oil. I'd pull the front diff cover ASAP to make sure the gears and oil look ok. Any shop should be able to do this.

Actually I have not changed it but now am planning to as soon as spring hits. When I bought it they replaced the gasket so it was replaced then. I'll keep it in 2 wheel drive unless we get 3 or more inches of snow. If I go in 4 wheel I'll be going under 30 MPH. The new BF Goodrich All Terran tires on the rear seem to do very well with the light snow.
The shop said he could feel the front and it felt ok just a few shavings. Hope I don't have to replace the whole gear when I change the fluid?

 

[rsh4364]

If roads are snow and ice covered I lock in the front hubs and put in 4wd high and drive 55-60 mph, no problem, my truck is a 86 1009 with 4.56 gears front and rear. I am on my 3rd winter with this truck, no problem. In 4wd low I would limit the speed dramatically.

 

[sandcobra164]

Go to "Randy's Ring and Pinion" and look up our application for a M1009 . You will see the front differential has a ratio of 3.08:1 while the rear has 3.07:1 . The M1028 had a ratio of 4.56:1 in the rear. I don't know what the front is though. All 4X4's have this. The only ones that do not are the constant 4X4 units. I rebuilt differentials for decades and this is the norm.

Mr. Greg,
I know you are a wealth of knowledge so I want to pick your brain just a little. My wife's 2WD Tahoe has a 3.08 rear axle ratio. It's a 2009 model and other than the disc brakes, looks about like any other 10 bolt. I've never heard of a 3.07 ratio available on a 10 bolt rear axle and 3.08 is a very common ratio across GM's product line for many years. As for the truck CUCV's, they typically have a Corporate 14 bolt in the rear and a Dana 60 front. Both are geared at 4.56 to 1.

Respectfully,
Joseph