1975 K-10 Project

[brennent]

As I continue to procrastinate replacing the transfer case rear output shaft seal and dozens of other really important things.....

I replaced the faded rear hubcap 4X4 inserts.
Love that groovy 1970's yellow and orange.

How do you like those wranglers? I was looking into getting a set for my truck? and if you dont mind me asking how much did you pay for them?

[BBM3]

The 30 - 40% worn, curb crashed, sidewall bulged Wranglers came with the truck.
No complaints.

[BBM3]

Subject: 1975 K10 with Dana 44 front axle.

I last week in the snow I noticed the front end of my truck is binding? bucking? (not sure the term) while turning in 4WD.

Today I am in the process of replacing the front axle u-joints assuming that was the cause.
Unfortunately when I removed the left axle I found an old but tight u-joint rather than the loose u-joint I was expecting.

So when I finish I will have two new Spicer 5-760x front axle u-joints but most likely the problem will persist.

In hindsight I should have lifted the front tires, turned the steering lock to lock, and spun the tires by hand before tearing the front axles apart.

In foresight I now have a hands-on understanding of the elegantly simple inner workings of the Dana 44.

[blazer74]

If it's automatic trans and is unmolested you have full time 203 transfer case. You have constant 4x4 engaged all the time.
When your driving on pavement you should be in the H position not H loc on the transfer case.
The sensation you are encountering is normal is H .
If in H loc you will really feel the binding.
Does it have locking hubs on the front axle?

[enaberif]

That whole binding/bucking will partially go away after changing the ujoints but you probably also have a NP203 which won't help either.

[BBM3]

That whole binding/bucking will partially go away after changing the ujoints but you probably also have a NP203 which won't help either.

Thanks for the reply.
I have an NP205.
I noticed some binding in 2WD with the hubs locked also.
The truck turns fine with the hubs unlocked in 2WD.

[BBM3]

If it's automatic trans and is unmolested you have full time 203 transfer case. You have constant 4x4 engaged all the time.
When your driving on pavement you should be in the H position not H loc on the transfer case.
The sensation you are encountering is normal is H .
If in H loc you will really feel the binding.
Does it have locking hubs on the front axle?

Thanks for the reply.
I have an SM465 and NP205 with manual locking hubs
The problem happened in deep snow. I would never lock the hubs and use 4WD on dry pavement.

[Greybeard]

Do both front wheels pull equally in the snow going straight? Not supposed to in normal conditions. Easy enough to peek inside the housing to see if anything unusual has been done to the diff.

[BBM3]

Do both front wheels pull equally in the snow going straight? Not supposed to in normal conditions. Easy enough to peek inside the housing to see if anything unusual has been done to the diff.

Brilliant idea taking the diff cover off and rotating the entire assembly from end to end while I have everything else exposed.

Thanks!

[Greybeard]

You have the ultimate strong stock drive-train there, minus the rear axle and housing. Ditch the 12 bolt and bolt in a 14 bolt FF and that trucks drive-train will be near bullet proof for what you will use it for. Keep the 12 bolt and fear every time you pull a stuck vehicle out of a snowbank. Changing the front bolt pattern to eight lugs is easy too.

By the way, do a close double check on the tire pressures and sizes. Any major discrepancies between front and rear will cause this bucking. If the t-case does not want to shift out of four wheel easily, it is definitely binding up. The 205 does not like any type of traction in four wheel drive, meaning if one wheel on each axle is not free to slip during a turn, it will buck. And front to rear binding (inside the t-case) is due to turning or different sized rolling radius's front to rear. I found that out myself early in my 4-wheeling days when I had a flat that wasn't fixable with my 36 inchers. A buddy had two 36 inchers of a different brand I put on till I could afford new tires. It snowed, I put it in four hi and promptly lost the ability to move forwards without the truck seemly jumping off the ground every five feet and steering becoming erratic. The mismatch in size was about a 1/2". I would bet that a smaller mismatch would still cause t-case binding, just to a lesser degree.   

[frotosride]

I don't think you have any actual issue. What you are experiencing is under steer due to the front tires trying to pull. This is why it only happens at and or close to full lock. If it is happening well before this it is likely your u-joints. Prior to replacing my u-joints I couldn't turn but half lock in 4wd without this problem. If you had a little less traction in the snow you wouldn't feel it as much.

[BBM3]

Thanks for the thoughtful replies.
Some more background:
I have OE size 235/75R-15 tires and pressures are to spec.
I rebuilt the transferase last year and it shifts smooth as butter. When I had it reassembled on the bench without the detent balls and springs installed I was able to shift it throughout the full range with two fingers.
The driveshaft u-joints are all good.
I have not taken the right axle apart yet but I have gently applied some pressure to it with a pry bar and it seems tight.
Regardless, I am replacing it after I finish the left side.

I don't think you have any actual issue. What you are experiencing is under steer due to the front tires trying to pull. This is why it only happens at and or close to full lock. If it is happening well before this it is likely your u-joints. Prior to replacing my u-joints I couldn't turn but half lock in 4wd without this problem. If you had a little less traction in the snow you wouldn't feel it as much.

This is is exactly what I experienced last week in the snow. I felt it way before full lock in forward and reverse.
That is why I blindly decided to replace the u-joints.
I hope to finish the front u-joints today. I'll report back once I'm finished.

Thanks again everyone.

[frotosride]

You will get the same thing on a 4wheeler or UTV when in 4wd when your front tires get traction especially on a hard surface. Especially if you have larger tires in the front

[BBM3]

I understand the physics on dry pavement / high traction surfaces.
I am concerned that my truck is a bucking Bronco (Go Broncos) even in deep snow at far less than full steering lock.

My plan to finish installing front axle u-joints today hit a snag when I realized I don't have any wheel bearing grease.
I'm not going to reinstall the rotors without repacking the bearings. Oops.

[frotosride]

I'm not going to reinstall the rotors without repacking the bearings. Oops.

I would have to strongly agree with you on this. Not sure why but my gut says greasing wheel bearings is a great idea.