Driveshaft(s) rebuilt

[ZR91]

Sent: 7/16/2007 7:30 PM

I mentioned awhile ago that I rebuilt the 2 driveshafts in our 24' Minnie Winnie.

I had noticed an odd vibration only while decellerating, and a pronounced clunk when putting it in gear.

I had no idea how bad it was....
I jacked up the motorhome to change the gear oil in the diff.-To gain enough room to remove the diff cover-I had to jack it up under the frame on both sides and then let the diff hang down as far as it could. I could barely turn the driveshaft, even by trying to rotate the wheels. When I did, I heard a pop, and the U-joint behind the steady bearing broke in half. -The greater angle created by having the diff suspended was the final straw, I guess.
However the needle bearings were GONE under the caps ! It was just metal on metal.

So, I replaced all 3 original U-joints(with heavy duty greaseable ones) and the steady bearing,too. I also noticed the front portion of the driveshaft appeared bent and I had it straightened and rebalanced.

I am glad that I found the problem when I did, because the front section of the rear driveshaft letting go and dropping down at highway speeds is a pole vaulting stunt I do not want to attempt.

Jay

[Lefty]

Sent: 7/16/2007 8:09 PM

Speaking of "Pole-vaulting", about two years ago, a local State trooper was traveling on the interstate at about 65-70mph in traffic when his car suddenly launched 30ft into the air and flipped end-over end down the road. An investigation revealed that the front u-joint had failed, and the driveshaft had contacted the gap in the roadway just right to get a good bite. He was only slightly injured, but I'd bet he had to go home & change his shorts afterwards!

[denisondc]

Sent: 7/17/2007 4:34 AM

I used to wonder why this didnt happen more often - having fixed several disintegrated u-joints on driveshafts, back in the days when the only front wheel drive cars were 3 cylinder Saabs and DKWs.
Sometimes when an older pickup truck or SUV is passing me, I still think about it. Its another reason to travel the 2 lane roads, rather than multi-lane interstates.

[firehart2]

Sent: 7/17/2007 5:56 AM

I wonder why Ralph Nader never pushed Detroit into having some kind of sling installed around the drivelines so that could not happen?

[yellow8882]

Sent: 7/17/2007 7:44 AM

Funny!!! I remember my Dad joking about that after it happened to him in his "74 Dodge Transvan. Good thing he was sitting in traffic when it happened!!!

[firehart2]

Sent: 7/17/2007 6:10 PM

I dropped a driveline in a 64 Rambler when I was sixteen. I revved it up and put it in drive. All it did was go, Bang, rattle, rattle, rattle.

[ontheroadagain]

Sent: 7/17/2007 6:46 PM

driveshaft saftey loops are required  on each section of the driveshaft on school buses in connecticut they are very easy to make and install  and can prevent alot of damage to your exhaust, tanks, floor and anything else the driveshaft can smash when spinning like LaMachine the chance of catapaulting is pretty slim but the damage happens very quick at highway speed and can cost big bucks to fix so its worth it to take the time to make and intsall a couple safety loops

[denisondc]

Sent: 7/18/2007 9:44 AM

I may make up a driveshaft safety loop or loops. I have some surplus seat belts, would just bolt the ends to some bracket nearby.

[ontheroadagain]

Sent: 7/18/2007 11:12 AM

the seat belts are not a good idea they would melt from the heat of the driveshaft spinning on them i used a large u-bolt with flat stock welded to the two ends to bolt it to a crossmember i got the u-bolts from a truck spring shop for free they usually cut the old ones off  and install new ones they always have some cut ones in the trash they need to be at least 3/8" thick mine are like 3/4" make sure you make the long enough so the driveshaft won't hit it when the rear end moves.

[bluebird]

Sent: 7/18/2007 5:26 PM

If you're planning on doing something like this, make sure the loop goes all the way around the drive shaft. When they come loose they will do a lot of damage. If it can't go out the bottom it WILL come out the top. And that my friend, will scare the crap out of you. Been there, well allmost. I did have one come through the floor boards on one of my race cars a few years ago. Couldn't get the engine shut off quick enough. It is best to remove and check the joints in these old rigs. I just replace 2 in Sparetime, when I rebuilt the transmission.

Charlie

[Lefty]

Sent: 7/19/2007 7:57 PM

What I personally would recommend is that anyone interested in adding this safety feature, go to a local salvage facility that deals in medium to heavy duty trucks. There's usually at least one in, or near, any major city. For example, here in Birmingham there is Kurt's Truck Parts, and Kiplingers Truck and Trailer Salvage, and a couple of more.
Get a Factory made driveshaft loop from a dead rig. It will have the advantage of being professionally made, and designed to meet or exceed DOT Safety Requirements for Med. to Heavy trucks.
Due to the strength needed, I wouldn't recommend a DIY'er to make their own.

[camperguynj]

Sent: 7/20/2007 6:08 AM

Every weekend I drive past the "scar" in the road where Winnie's drive shaft dropped (center joint failed) The guy I used to fix and balance the shaft - Universal Drive-Line Service Co.- is posted in the resource section ... ( and pictures of the tow are in my album)

- Jim

PS - I got excited when I found and installed a retractable clothesline - meanwhile all you guys are under the rigs fashioning drive shaft brassieres outta seat belts and truck springs ... I think I got my priorities wrong

[ontheroadagain]

Sent: 7/20/2007 7:19 AM

thats i good idea but most trucks don't have them (they should but it cost money!) and the ones that do are fabricated they are found on mostly school buses, fire rescue and ambulances i've been repairing and fabricating vehicles for over 20 years so i forget that what is simple and common sense for me might not be for someone else. your absolutely right that it might be beyond the skill of a diy'er if so then it should be done by a qualified repair shop

[BrandonMc]

Can I ask why the u-joints in my winnie 88 p30 chassis have no grease fittings to lube them? Am I just to allow them to fail and replace because they are permanently sealed, or have I missed something here.... ? they are bone dry


thanks

[MotorPro]

How do you know they are dry?

[LJ-TJ]

Well there yeah go. Mine has a grease nipple inside the u-joint knuckle on both ends. Didn't know they made a universal joint with out a grease nipple. Yeah learn something new every day. D:oH!

[legomybago]

Well....Nothing lasts forever! Sealed bearings are good, and strong. Even if they had zurks, the seals would be toast by now and not let the grease properly fill the u-joint due to someone over filling them over and over....U-joints in my opinion are a fail part that need to be watched and checked during your annual inspection in your driveway....I think the only time I've really had an issue with a sealed u-joint that could fail prematurely is on the front driveline of my Land Rover, the front shaft is located right next to one of the catalytic converters, and the heat from the cat cooks the grease right out of the sealed u-joints and you have failure eventually, that usually involves poking a large hole in the side of your automatic transmission!! Its a known/common problem on the Land Rover, and you know the fix, serviceable u-joints!

[BrandonMc]

How do you know they are dry?

they are dry from the outside.

[legomybago]

they are dry from the outside.

They are supposed to be dry looking from the outside if the seals are still good, that usually means the grease is still inside them. If you have any doubt, you should remove and take it to a drive live shop and have them go through it.

[EldoradoBill]

I've had more issues with greaseable joints than the sealed ones-once they are over greased and the seal is breached it's the beginning of the end. Plus the grease fitting is the weak link-when parts break its usually at the hole drilled for the zerk.


Bill