Vibration at 45-50 mph

[surfnuke9]

OK,

My new 71 w200 has a driveline vibration from 45-50 mph.

Truck details: front dana 44 3500lb large closed knuckle (?) axle 4.09 gears, rear 5500 lb axle 4.10 gears

The tires that are on it have low miles on them (<2000), but they were manufactured the 7th week of 2001 (from the code on the sidewall).

I have not had them balanced yet and know this could be my issue, but want other troublsshooting avenues to pursue also.

Symptoms:

Constant between 45 and 50 mph, seems from the front more than the rear.

Driving in 3rd or 4th gear does not affect it.

Driving in 2-Hi or 4-Hi does not affect it.

Does not change with clutch engaged or disengaged.

Does not change with brakes applied.

Does not change with steering right or left.

U-Joints are in phase and straps are tight. I have not pulled any u-joint caps and looked for any signs of wear on any of the drive shafts.

Thoughts?


Oh yea, while turning and moving the truck very slowly, I can hear a sound much like popping your knuckles from the front. (axle u-joints?) I know this may be a sepearte issue and due to only 2000 miles put on over the last 10 years.

Thanks,

[digdoug]

Besides tire balance, it is a good idea to jack up the front of the truck,grab hold of the tire ,and check for play.Loose wheel bearings,loose spindle,loose trunnions,loose tierods,loose draglink,loose pitman,loose steering gear,worn spring bushings,all can be a cause.

[surfnuke9]

removed the front drive shaft today to try and isolate the issue.

the splined portion of the shaft was loose and has some wear.

With the shaft removed, the vibration and shudder is almost gone.

Ujoints seem very tight.

front pinion has what feels to me like some significant gear backlash. can rotate the pinion shaft about 10 degrees or so by hand.

gonna run for a bit without the front shaft and see how it does.

Guess I nee to find a new shaft. anybody make them? Not interested in getting another used worn shaft.

Still know that there are most likely some front end issues playing here also. will get to them as time permits.

[sweatybetty]

unless you are driving around with the t-case in 4hi or your front hubs locked in, the front drive shaft shouldnt turn while driving, so no vibration.
as far as "phasing" drive shafts, as soon as you go into 4-lo they are out of "phase"
i would
1 have tires balanced. if that doesnt cure the vibration,
2 have the short and rear drive shafts balance checked

[surfnuke9]

Since I dont have manual locking hubs on the front, the front driveshaft will turn when the front wheels turn.

The phasing I was referring to was the u-joints on the same shaft.

[mowingman]

I had front drive shaft with the same problem, on my 69, W200. I had a new one made at a truck repair shop. Anyplace that repairs or makes drivelines, can do one for you.
Jeff

[injunjoe]

I would take a close look at the upper bronze cone bearings on the steering knuckles. The lowers are tapered roller bearings. Jack up one side and shake the wheel around it is common for those bronze bearings to get sloppy from lack of oil. The gear oil in the closed knuckles only gets up there with use.

[surfnuke9]

OK, reviving my old thread.

found anew spline yoke for the front driveshaft. Installed with new u-joints. much better but still have some vibration at ~50 mph.

What size/series u-joint is used on the front axle (inside the knuckle) ?

I plan to start gathering the parts to rebuild the knuckle, bearings, cones, etc....

Thanks,

[digdoug]

http://www.vintagepowerwagons.com/

[Russ]

OK, reviving my old thread.

found anew spline yoke for the front driveshaft. Installed with new u-joints. much better but still have some vibration at ~50 mph.

What size/series u-joint is used on the front axle (inside the knuckle) ?

I plan to start gathering the parts to rebuild the knuckle, bearings, cones, etc....

Thanks,

The u-joint in the knuckle isn't a standard joint like the ones on the driveshafts, but it is repairable if you can find the parts. Have you checked the lube inside the knuckles? It should be 140 weight but many times the seals start leaking and they get filled with grease, which does nothing to actually lube the u-joint after a while. Also, like someone already suggested, jack up one wheel, put your hands on the top and bottom, and see if you can move it any. If it has a lot of play the pivots are worn, but I don't think worn pivots would cause the clicking you mentioned.
BTW, there are two different style upper pivots. You will need to know which you have before getting new ones. One is keyed and the other has splines in the center.

[surfnuke9]

Thanks for the tips.

I could swear I read in the service manual that the knuckle was lubed with grease, not 140 weight.....

Will look again.

[surfnuke9]

steering knuckle uses grease, differential uses heavy weight oil...see step (13).

[digdoug]

There has been much discussion on this topic. There are two different lubes speced in two different places. No.2 grease is too heavy. it will get flinged to the outside of the knuckle and stay there,leaving your u joints running deprived in the remaing air cavity.

I have been running John Deer "Corn Head Grease" in my closed nuckles for 20 years with much success. It starts melting at a little past 100 degrees,letting it work the way you need it to,without alot of leaking . There are many other greases of this type. I would look for a 00 or 0 .
https://jdparts.deere.com/partsmkt/docu ... urpose.htm

www.lubricantsusa.com

[surfnuke9]

OK, that is good to know.

tractor supply or some other place I should look for that grease?

[Hobcobble]

Another FSM said something about short fiber grease. I asked a lubricants
manufacturer I do business with..... bought what they recommended and
shot it into the knuckles. I started with 140W and new felts and seals. Within
days... it was weeping out. With the grease.... no issues yet.
John

[surfnuke9]

never one to shy away from asking the dumb question....

what is "short fiber" grease? never heard of it.

what did they recommend to you?

[Russ]

In my 69-70 FSM it says to fill the knuckle with SAE 140 to the level of the filler plug opening. This makes sense to me because the only way the brass upper pivot will get lubricated is by the oil slinging from the u-joint. The upper pivot has diagonal slots cut into it to allow the oil to run down and be distributed on the race as the wheels are turned back and forth. I also have a Motors Truck manual that says that the truck should be driven with the hubs locked at least once per month to lube the upper pivots. I don't average driving my truck once per month so I just leave my hubs locked. I rebuilt my front axle in 2000 when I converted my truck to 4X4 and haven't had a problem with the hub seals leaking. I got all of my parts, including the seals, from the local Dodge dealer so it's possible that they might be better quality than some aftermarket seals. It's never been on a dirt road since then so I guess it's not a really good test of the seals.

[Hobcobble]

never one to shy away from asking the dumb question....

what is "short fiber" grease? never heard of it.

what did they recommend to you?

Never being one to shy away from an individual who doesn't shy away ....
It was explained to me that "short fiber" grease is, in general, comparable to
wheel bearing grease. The lubricants blender also added that you can "cut" it
very slightly with 140W oil to change its viscosity. As I had a tad bit of 140W
still left in the knuckles.... I merely added the grease, locked my hubs and
drove it around. I have not had any issues with seepage since.
John

[surfnuke9]

Since I dont have lockable hubs, it stands to reason that I am always getting some grease/140W slinging around in there.

assuming my grease hasnt turned into asphalt.

Thanks for the answers guys.

[VintageMopar]

If you are still having the vibration and haven't already done so, I suggest you check your front bearing retainer on your transmission. Some slide-rule jockey at Chrysler convinced them to use the same size throw-out bearings in trucks as cars, which required reducing the diameter of the front bearing retainer beginning in 1969 model year, and they are prone to breakage. 1968 and older are bigger and I haven't heard of one breaking. The truck can still run and drive w/ a broken front bearing retainer, but there will be vibration and noise; eventually you won't be able to engage the gears.