I notice a bump in the drivetrain while accelerating from a stop, and sometimes while bringing the vehicle to a stop. I've read some posts where the slip yoke seem to be the cuase. The Dealer has replaced this part, as well as a U-Joint bushing. Yet I still experience the problem. I'm alreading down about $600 trying to get this fixed. Has anyone else who had this problem had it solved or know what it could be?

 

Sorry a little more info, 1997 F150 4x4 long bed 4.L V8,82,000mi

 

I know what you mean mike311 I also have a 97'' F150 4x4 and its doing the same thing yours is. Everytime I go to take off it makes a bump noise like theres play somewhere in the drive train. I have left post in this forum and in FTWs forum, only had one reply and he said it was prolly the slip yoke that needs to be greesed.......But from what I know the yoke is splined so what will greese do? But you know what.....mine doesnt do it in 4x4 so its really weird.

Let me know if you here anything, and i'll do the same

Jimmy

www.ftwtrucks.com/1HIGH4BY/

https://www.f150online.com/galleries...y.cfm?gnum=3950

 

Well you are in luck, after spending 600 bucks, 140 to diagnose, and 460 to replace the slip yoke, i still had the problem, it actually got worse.

I took it back to the ford repair shop and they said they would try to fix it again.

Turns out grease was the anser. They greased it up, and no more bump. Runs great.

Why they didn't try that first is beyond me.

I'm going to call customer service to trying and get some of the money refunded.

 

You got to be kidding me The only problem was grease. If you think about it greaseing it doesnt seem like it would fix it.....Cause the yoke is splined so there shouldent be any play.....but hey, greasing it works for me


Well your the second person to tell me that so it must be right.

Thanks for the help mike

Jimmy


www.ftwtrucks.com/1HIGH4BY/

https://www.f150online.com/galleries...y.cfm?gnum=3950

 

we use the teflon blue grease on those splines so they dont bind up. but once they dry they can become damaged and not let the yoke slide propperly. that tech probably forgot to grease the new one when he put it in.

we always try grease first and ask the customer if they are satisfied if not then they get the yoke. but most times they are happy with the grease thing is they might be back in 30k for more grease. where the new yoke might last longer because it is not burred up or anything.

 

Thanks alot guys I went to autozone and bought some real good grease and pulled my drive shaft off and lubed up the yoke....and guess what, no more bumping noise. I am so amazed what greasing the yoke could do. I would have never ever thought of this to be the problem.
Thanks again guys for your help....you saved my alot of $$$

Jimmy

www.ftwtrucks.com/1HIGH4BY/

https://www.f150online.com/galleries...y.cfm?gnum=3950

 

I have a 2001 Supercrew 4X4 with the exact same symptoms.

The Local dealership told me that this was a very common Ford problem and told me to do exactly that same thing. get some TEFLON grease (it took me a while to find out that PTFE was the same thing probably without the licensing fee to be paid to Dupont for using the name TEFLON) and lube the Yoke.

I haven't gotten around to it yet but I Will eventually. Glade to hear the it fixed it for ya.

Dpostman

 

I am so glad to read about the solution to this problem, I just bought 1 98 F150 used three days ago and I felt the vehicle ran fine except for this noise, it has 120,000 so I was thinking I might need a rear end, I hope the grease works, is taking the driveshaft off a complicated endeavor? Do you need a lift?
Is there any special place to put the grease?, Thanks

 

Glad to see there is a relatively easy/simple fix for this. I have a 2001 SCrew 4x4 with the 5.4... I had this problem almost since I bought the truck. Just before it went out of warranty I had it addressed and they replaced the slip yoke. The problem came back months later. I have put up with it ever since.

Now the dumb question... What exactly is a slip yoke/what does it do?


Also, will it cause more damage to drive it while it is doing this bump every time you start from a dead stop?

Thanks!

 

There are two slip yokes on a two peace driveshaft, I think they are talking about the one in the middle at the carrier bearing, but they do not say. There is not much movement at the transmission slip yoke, I always though the oil in the transmission lubricated it, as it has no grease fittings. But I could be wrong.

The slip yokes let the driveshafts get longer and shorter and slips on a spline shaft.

I would like them to tell if it is the front or rear yoke they are talking about. .

 

There is only a 1 piece Drive Shaft on a 4X4 SuperCrew. The Slip Yoke is the part that the Driveshaft is attached to that enters the transfer case. There has to be some play there to accomodate Empty of full payload in the bed of the truck so you'll see about a 1/2" of wear on the outside of the slip Yoke where it enters the Transfer Case. The First time I tried to grease it in November 04 with the Blue Teflon Grease, it lasted only about 2 weeks. The last time I Greased it, I think in March 05, I used a Pure Silicon Grease. It is very Pricy but it's still running fine

The GE Versilube is no longer availiable but this is it's replacement:



EDIT TO ADD: Greasing implies the inside of the slip Yoke where it slides onto the spline.

Have Fun

Dpostman