Small Front Driveshaft...

[silveradoking]

I have the terrible chainsaw effect on my truck.....clunk, clunk a do doddle do......Anyways, today when I was under the truck I noticed that the front driveshaft, the small one about 1 in a half to 2 feet long on a 4 by 4 vehicle that it moves about 1/4 inch or so either way when the wheels are on the ground......Like if you grabbed the shaft and tried turnign it, it moves a lot.....side to side.....Is this normal? Could it be that I have to change the u-joints.....makes me wonder if this could solve one of my clunking noises......Anyone know?

[airtight_python]

I'm not too familar with 4x4s but on a 2wd it isn't supposed to have play. You might check out those u-joints. They dont cost too much.

[Silverado Brethern]

A 2wd drive doesnt have a front driveshaft. But anyway im pretty sure this is something rather common that happens over time. Both of my driveshafts do it, really bad in the rear. A questioned a mechanic about it and he said that trying to fix it and keep it fixed is a battle you likely wont ever win cuz the new u-joints will go bad quickly. My front shaft doesnt clunk, just a loud whining noise when in 4wd.

[TXAGG05]

My front drive shaft probably also has about a 1/4 inch of play or more. Silverado Brethern is right, you'll be replacing U-joints quite often if you want to totally eliminate the problem. My rear doesn't have too much play in it with the wheels on the ground,....but there's definitely some play there.
You need some play in it so if you get into something where you have the drivetrain wound up pretty tight and you need to shift from forward to reverse, or vice versa(at least that's the dealer's excuse). It would seem that drive shaft play is very common in these trucks, but what do you expect, it's not a dainty european sports car.

-Jeb

Oh, Brethern, my 4wd also whines a lot. Has been doing it for about a year now. Have you tried switching to synthetic gear oil? I think I'm going to put Royal purple in after I replace my front seals.

[silveradoking]

thanks guys for the replies.....So basically it's a waste of money....but if I changed the u-joints in the front....would there be no play? and how long would it roughly last? On my rear driveshaft, it doesn't move at all.....guess I am lucky.....

[Silverado Brethern]

I honestly think its something in the transfer case that causes all the clunkage. Most likely a result of age and use. New U-joints could keep it quite for a year or it could just be a month, depends on the age and condition of the differential and gears.

Jeb- No i have not tried any type of synthetic oil, actually i have not touched anything. I know that my front seals are leaking but the levels are still fine. I just think the whine is from the wear in the gears but a better gear oil may help delay the wear.

[airtight_python]

Didn't mean to sound stupid. I am aware 2wd vehicles don't have driveshafts. Mine doesn't have play but it has a clunk... weird.

[TXAGG05]

Yeah,...I noticed the other day that mine are leaking too. I think once some of this work slows down I'm going to replace the seals and then change front/rear diffs and x-case with Royal Purple. Though, I'm a little worried that maybe with the miles on my truck I might cause leaks in the rear axle seals by putting in synthetic.

Jeb

I have to run a a few miles down a sand/mud road on my ranch and if it rains then I have to run in 4-hi. The whine is really irritating at about 30 mph on the sand. Hopefully I can do something to quiet it down. I've had 4x4s that make more noise when engaged, but this is a little much for a newer truck, and I don't remember it doing it when it was new.

[pies]

99 and newer trucks have synthetic in the rear axle and regular 89w-90 in the front diff. i was told not to put synthetic in the front due to the fact that the front diff runs alot hotter than the rear when in 4 wheel drive. tried it anyways and found that the seals really leaked bad with synthetic in the front.

[TXAGG05]

Yeah, I have synthetic in the rear. I have to replace the front axle seals anyway, so I figure it shouldn't leak after that. I read somewhere that the synthetic fluid actually keeps the gears cooler and most importantly, I read that it keeps the fluid from "turning to mud", which happened once already in my front diff and I blame it for the bad seals.
I'm confused as to how synthetic fluid wouldn't be able to stand up to the heat in the front diff. Correct me if I'm wrong, but isn't synthetic designed so that it doesn't break down as easily as regular oil?

Jeb

[pies]

synthetic oils have a thinner body than mineral based oils. takr some 75-90 syngear and 80w-90 and heat them both up to 100 degrees. the synthetic will be as thin as water , while the 80w-90 will still have some body to it.

[silveradoking]

I had to revisit this older post because I think I goofed....When I turn the small driveshaft in the front, I had stated that there was play in the ujoints....but one of my friends said to me that the play has to be between the yoke and the driveshaft it's self....In that case I guess the ujoints are ok on my truck.....But when I turn the driveshaft, the shaft it's self, along with the ujoint and the yoke turns all together....I hope this makes sense.....So I am thinking could ths mean that the yoke is gone, or maybe something in the transfer case or.....what do you guys think......

[steelieagw81]

Originally Posted by silveradoking

I had to revisit this older post because I think I goofed....When I turn the small driveshaft in the front, I had stated that there was play in the ujoints....but one of my friends said to me that the play has to be between the yoke and the driveshaft it's self....In that case I guess the ujoints are ok on my truck.....But when I turn the driveshaft, the shaft it's self, along with the ujoint and the yoke turns all together....I hope this makes sense.....So I am thinking could ths mean that the yoke is gone, or maybe something in the transfer case or.....what do you guys think......

Change the front shaft U-joints you may not have play but if you havent changed them in a while and use 4wd a lot they are probably dueI have experienced both of your problems change the . I too had the whining in the front T-case put mobil-1 75-90 whining gone the fluid that came out was mud i have talked to quite a few people that have had the same problem and seems to cure the whining I've got 6 months and 10000 on the change of fluid and no whining and everything is all original.

[who fan]

My truck is a 01 Z71 57300 miles. It has the rotating play in front driveshaft I just figure its back lash in the transfer case chain. Chevys are good trucks but unfortunently they don`t have Swiss watch precission. For the price they should lol! Mine also has the CSK. Lifes short, drive her til she drops. GM can do better. Next time around they better. I like my 01 but I kinda think the 88-98`s were better. I miss the 350.

[mickey g]

Originally Posted by silveradoking

I have the terrible chainsaw effect on my truck.....clunk, clunk a do doddle do......Anyways, today when I was under the truck I noticed that the front driveshaft, the small one about 1 in a half to 2 feet long on a 4 by 4 vehicle that it moves about 1/4 inch or so either way when the wheels are on the ground......Like if you grabbed the shaft and tried turnign it, it moves a lot.....side to side.....Is this normal? Could it be that I have to change the u-joints.....makes me wonder if this could solve one of my clunking noises......Anyone know?

The small drive shaft in front is your four wheel drive driveshaft. I have a 99 silverado Z71 and mine has that same problem. I took it to a mechanic and he said the play in it was normal. You just have to get used to the wierd sounds chevys make. If it gets on your nerves too bad, just take it off and you won't have 4 wheel drive. It's going to always make the wierd sounds, but don't worry its normal