Engine/Transmission (1998.5 - 2002) Play in output shaft / yoke

[KrisKringle]

Ok...In a recent inspection of the truck, I noticed that the U-joint at the transmission yoke (NV4500) had some play. I replaced all of the U-joints and centre support bearing around 50K miles ago (in 2011) when I bought the truck. (136K miles). More importantly, I notice play in the output yoke and the main-shaft. A bit of background of the truck:

1. The truck comes from Waco Texas, and had a fifth wheel before the PO bought it with 100K on it.
2. the PO was/is a bit of a yahoo, and never knew about the maintenance of the trans and rear, as per fluid change intervals.
3. The rear seal was weeping when I did the drive shaft overhaul.
4. Now the leak is of the dripping variety.

The questions are:

1. Is it typical for the yoke to wear, or must I consider changing both the Main-shaft and yoke.
2. I have very seldom seen a U-joint fail at the trans when there is a centre support bearing; what is the cause?
3. (Info A bushing (tail shaft bushing) is already on the way. Damn Fiat! Few parts are available here (in Germany) for the truck any more.

If the replacement of the main-shaft is recommended, then I will do an entire transmission overhaul. Unfortunately, this is my busy season, and down-time is not really an option. I am not one to do "pity-Patches" either...HELP

I use the truck for relatively heavy hauling; over 7K tonnes. (That would be over 12K pounds in the States, including load on the truck and the trailer. Needless to say, I will not be doing this until the issue is resolved.

I have included a picture of a "light" load. In the coming months I have several projects in Holland, where I will be required to haul over 15K in Material including truck load and trailer. Thanks for your help. Jonathan.

 

[GrantP]

Did the yoke have any wear around the seal surface or tail shaft bushing area? If you can feel some ridges you probably need a new yoke. Otherwise a new tail shaft bushing and seal should fix the slop and leak. I really, really doubt that you need to replace the mainshaft due to wear.

 

[KrisKringle]

Did the yoke have any wear around the seal surface or tail shaft bushing area? If you can feel some ridges you probably need a new yoke. Otherwise a new tail shaft bushing and seal should fix the slop and leak. I really, really doubt that you need to replace the mainshaft due to wear.

When I replaced the U-joints in 2011, there was no ridge on the yoke, Rock Auto shipped the wrong seal, or I would have replaced it then. What worries me is that the U-Joint at the transmission has play in it, whereas the ones on the second half of the driveshaft do not; the one at the trans is static since it is supported by the centre-support bearing. (to state the obvious). It could just be a duff unit from Moog.

 

[B.G. Smith]

If you are talking about play in the yoke where it extends into the rear of the transmission the new tailshaft bushing should cure that. The fast that the tailshaft of the transmission is able to move that much is not revelant as it is only supported at the rear of the transmission houseing by a tapered roller bearing. You will need a special tool to replace the bushing. bg

 

[Ozymandias]

Wieviel Spiel hast du den, nur spürbar oder auch messbar?

Gruss Ozymandias

 

[KrisKringle]

Wieviel Spiel hast du den, nur spürbar oder auch messbar?

Gruss Ozymandias

Ich glaube daß die Standard Sprache des Forums Englisch ist. Jedenfalls, Die Spiel ist meßbar: die Gegenschlag ist +/- 3 mm auf den Keilen von der Abtriebswelle

LG aus Kürten.

I believe the standard language of the forum is English. Anyway, The play is measurable, and is + / - 1/8 inch on the splines from the output shaft.

 

[KrisKringle]

If you are talking about play in the yoke where it extends into the rear of the transmission the new tailshaft bushing should cure that. The fast that the tailshaft of the transmission is able to move that much is not revelant as it is only supported at the rear of the transmission houseing by a tapered roller bearing. You will need a special tool to replace the bushing. bg

I was not refering to lateral or axial movement of the yoke, but rather the radial play in the splines. As far as replacing the bushing, I have the tools here. Thanks.

 

[HHhuntitall]

It is not uncommon for the any of the U-joints to fail with some mileage. Poor lubricant quality is usually the culprit from the factory, however, looking at your picture, I'd say usual wear and tear has taken it's toll. Torque hammer from these little Cummins engines is rather harsh on drivetrain components designed for gas engines with half the torque and twice the RPMs. Personally, I'd pull the shaft, check the carrier bearing, have the U-joints replaced, and check the balance, if a competent driveshaft shop is available.

Not sure if you want to go this route, but for myself, having multiple vehicles, I have spare driveshafts for just such incidents. A company called Driveshaft Specialists in San Antonio, Tx builds complete shafts pretty reasonable, you might consider a new shaft, if you want less downtime..... Just a suggestion. www.driveshaftspecialist.com

I have used these guys for a number of years, an many project trucks, and their prices are usually much cheaper than specialist shops or driveline shops. Fort Worth Gear and Axle also does some custom work. I have had them make me some shafts for Jeeps and lifted trucks a few times, as well.

 

[B.G. Smith]

Please let us know what the final solution turns out to be. bg