Front driveshaft u joints?

[forrestvt]

Searched around on the forum but didnt quite get my question answered....

I have an 88 FJ62 that when in 4wheel drive traveling at speeds ~45mph higher gets what I think sounds like front driveline wobble. So I inspected the front driveline inplace, no movement at the u joints and no apperent problems. So I pulled the driveline off for closer inspection and still nothing, all appears tight and in good working order to my rookie eyes. This cruiser is a recent purchase so I dont know when or if the u joints were ever replaced and the rig has about 220,000 miles on it. I was going to drop of the front driveshaft at a local shop in town and have them replace the u joints. Am I on the right track here?

cheers!

 

[Cruiserdrew]

Searched around on the forum but didnt quite get my question answered....

Am I on the right track here?

cheers!

No. Those front u-joints have virtually no wear. You youself said they were tight. Remember, unless you put it in 4 wheel drive, or lock the hubs, they are not turning.

It's likely just the rotational speed speed and the incorrect geometry of the driveshaft flanges. It isn't set up parrallel, so it will vibrate at high speed. It's just the nature of it. Read up on proper u-joint geometry and you'll understand instantly.

Read this, Roger Brown has an amazing website:Driveline 101

 

[lcwizard]

Have you greased the u-joints and spline lately?

 

[cruiser_guy]

It's probably as "Cruiserdrew" is saying, out of alignment on the "U" joints. You don't just slide the two halves together you NEED to align the joints to avoid vibration. The shop manual describes it well.

 

[Cruiserdrew]

It's probably as "Cruiserdrew" is saying, out of alignment on the "U" joints. You don't just slide the two halves together you NEED to align the joints to avoid vibration. The shop manual describes it well.

No, the point is the front cannot be set up right. The T-case output points up, the pinion points up, so there is no arrangement where the flanges are parallel.

The only vibe free way to set it up is with a double cardan and the pinion pointing exactly at the t-case.

I think it's just the speed, coupled with some wear and it vibes a little. No big, you souldn't be driving 45 in 4wd anyway.

 

[forrestvt]

Appreciate the responses! I marked everything when I pulled it off but I believe the driveshaft must have been removed at some point in the vehicles past so.....I lubed everything up and put it back in...helped a little but I will have to locate a manual to read up.

Driveline 101 was an informative read...saved that one for future reference.

My modified 60 is able to cruise at 45 in 4wd no vibrations so I feel this 62 should be able to since it is in stock form. On AK highways in the winter you often need to be in 4wd to get anywhere so 45-50 mph is achieved on the long flat straight aways.

Well, thanks again and I'll keep you posted.

Cheers!

 

[cruiser_guy]

If the slip joint has been pulled apart and the "U" joints not lined up with each other when the shaft is put together then vibrations occur. My '60 runs smooth at speed in 4wd as well so it IS possible.

 

[Mace]

No big, you souldn't be driving 45 in 4wd anyway.

Bah, humbug

 

[lehiguy]

Bah, humbug

!!!!!!! I confess to doing about 70 in four-high on I-15. That's why I installed those expensive CV joints on both my drivelines, right?