I have the 4R70W auto trans in a 98 f150, and have now blown the rear seal out of the tailshaft twice. First time at about 155,000 miles (90mph) and now at 158,000 miles (75mph). It looks like the bushing is also bad. Anyone with any advice? I'm planning on replacing the bushing and putting in a new seal, but don't know if this fixes the real problem.

 

As far as I've found you can't purchase the bushing alone it comes complete with the extension housing $180 cnd dealer only seal extra.The slip yoke seems to be on the sloppy side on mine so I'm looking to fix it before I have problems.

 

Thanks,you were right. Dealer only item, you have to replace the whole tailshaft extension. Cost was $112 US, included a new seal. Now I just need to get under there and replace it today.

 

ACEB--> Check out my thread "Is this tranny shudder??" Was you getting any deep sounding vibraton in the cab when you blew the seal
Based on the replies I got, the problem MIGHT be drive shaft related. Better yet, the limitations of the shaft. I'm having the whole drive train checked out at the same time they install my JBA headers.. I'll post results.

 

I blew a seal on my 96 at 90k miles after a road trip. The tranny guy I took it to said he'd never seen that sort of thing, but bad u-joints could have caused it. I had just recently replaced the u-joints before that because they were bad. I'd check those joints if I were you, and while you have the driveshaft out, take it to a shop to make sure it is perfectly straight.

 

Driveline/Extension Housing - Vibration/Leaks
Article No.
01-9-3

05/14/01

^ VIBRATION - FROM DRIVELINE - 4X2 VEHICLES
WITH 4R70W AND 139 INCH WHEELBASE

^ TRANSMISSION - 4R7OW - FLUID LEAK FROM
EXTENSION HOUSING SEAL - 4X2 VEHICLES WITH
139 INCH WHEELBASE

FORD:
1997-2000 F-150, F-250 LD

This article is being republished to update the model year coverage and to update the part application.

ISSUE
A driveline vibration and/or a transmission fluid leak from the extension housing seal area may occur on some vehicles. This may be caused by the extension housing bushing or seal walking/spinning out due to excess driveshaft flexing during extended high speed operation.

ACTION
Inspect the extension housing bushing and seal. If the extension bushing/seal is spun and/or walked out, replace the extension housing assembly and gasket with new service parts, and replace the driveshaft with a revised 127 mm (5") diameter driveshaft. In addition, some vehicles will require the balance marks on the driveshaft, output shaft, and rear axle flange to be aligned so a repeat condition will not occur. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Raise the vehicle on a hoist and inspect the transmission extension housing bushing and seal for damage. In addition, inspect the driveshaft diameter. The revised driveshaft has a 127 mm (5") diameter and the old part has a 114 mm (4.5") diameter.

2. If the extension housing bushing or seal is damaged, remove the driveshaft and transmission extension housing per the appropriate year Workshop Manual, Section 307-01. Install a new Extension Housing Assembly (F3LY-7A039-A), and a new Extension Housing Gasket (F6AZ-7086-A). Verify transmission fluid level.

3. If the vehicle is equipped with the 114 mm (4.5") aluminum driveshaft, replace the driveshaft with the revised 127 mm (5") Driveshaft (see parts list for application).




OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 99-26-2
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

010903A Replace Extension 1.6 Hrs.
Housing Assembly;
Driveshaft When Required
(Includes Inspection Time)

DEALER CODING
CONDITION
BASIC PART NO. CODE
4602 42

OASIS CODES: 501000, 502000, 503000, 504000, 510000, 703000, 703200, 703300, 703400

 

Ajragno , thanks for thr info . Did Ford fix your problem ??

I replaced the extension housing myself and got my driveshaft balanced (it was way off). I haven't had the change to run it yet. But I will soon.

 

I have not had a change to get it looked at yet. I was thinking of going to a transmission shop but considering that Ford installed a driveshaft from the factory that was too small, I am counting on them picking up part of the cost of a new, larger one.

I talked to a dealer service rep yesterday and he was familiar with the TSB.

He said he'd check on parts availability and call me back but I havn't heard from him yet.

If this is why my truck is vibrating, I am not impressed with Ford's additude. The TSB says this can happen after extended high speed operation but I've never been over 80 MPH, which just happens to be the speed limit between Minneapolis and St. Cloud, MN. My truck started having problems the day after I drove to St. Cloud and Back.

I would like to change the seal and bushing myself but I've never removed a drivshaft so I don't know what to expect and it's too cold here to work on it all day.

After I found the TSB, I did a search here under "housing" and "extention" and found that literally dozens of people have had the seal blown so this does seem to be an issue.

 

I also called ford and was told that they WOULD NOT reinburse my for the extension housing part . There reason was "the work wasn't done by a ford service dept"
I feel that this issue should more then a TSB. Can you say RECALL !!. If I still have the vibration after I test it, i'm going to replace the driveshaft myself. I'm not going to put my safety in ford's hands.
After all I do have installed mods that they can use against me.
Do you have a price on the 5 in driveshaft.

 

FYI...FYI

Based on the parts # IL32-4602-CA, or BB the cost for a new driveshaft is $330.18. You should also think about getting the new one balanced..

 

I'd like to know how many Ford owners have experienced the problem post by 'AjRagno"

 

This seems to be a common problem for anyone who drives fast and is not restricted to the F-150. I know that Neal had this problem a few years ago.

Ford's additude towards problems really gets to me sometimes. When you look at the dozens of TSB's, it seems as though they don't spend enough time researching real world use of their vehicles and then when parts break or design issues come to light, they issue TSB's and expect the consumer to pay for their lack of wisdom.

When I discussed the possiblity that this was the problem I have with my truck, the dealer service advisor told me that when the seal breaks it's very obvious because fluid pours out and considering that I don't have such obvious signs, he didn't think I should even bother having it inspected. He also said that he's never seen this on an F-150 but that after talking to other techs found that it's very common on Crown Victorias (I'm assuming the police model has had a few issues).

Considering that the transmission could loose enough fluid to leave someone disabled in freeway traffic, I think this is a safety issue and deserves to have a complaint filed by anyone experiencing problems. http://www.nhtsa.gov

My problem has gone from just an annoying vibration to a loud humming up front so now I'm thinking that a bearing has gone bad in my right front wheel. It's still too cold here in Minnesota to check or change it this week so I'm driving our Explorer till I have it looked at.

 

I took a chance and took the TSB (Driveline/extension housing vibration/Leaking) to ANOTHER Ford dealer today and told them what my symptoms were. To my surprise they informed me that they were aware of the problem and they would reimburse me AND replace the driveshaft ...

Sometimes it pays to be persistent..

I'll post results

 

Just got my 5'' driveshaft and new extension housing install. And all the vibrations and high speeds are GONE !! My ride is as smooth as silk ...
If anyone has experienced a deep vibration at high speeds
(after getting a good wheel balance) you might benefit by printing out the TSB that AJRagno posted and taking it into Ford..

THanks again AJRagno for posting ...

 

Does this apply to 4x2's only and does a fluid leak always occur? I have a vibration problem I am trying to solve on my 97 4x4 and wonder if this could be it. You can only feel the vibration at speeds greater than 40-50 but there is little to no noise.