E350 - Droning Noise (from rear?) at deceleration

[E-350]

Interesting info.

Regarding the angles... there are so many people out there lifting their van the way I did and don't complain... so can't really imagine that's the reason as I didn't anything "special". But didn't check yet...

I found that the bushing I replaced in the tail housing has some play again. So after I have now added the spacer I will do this $6 test again (to rule out I didn't destroy the new bushing without the spacer), once open take a video of the movement in my output shaft (just to have it on hand for any further discussion.

[Dearranged]

Mine is the 6.8l engine which uses the 3.5" driveshaft, the listing for the 5.4 and 6.0 use a 4" driveshaft. Go figure.

[E-350]

Not giving up guys! :-DDD still on it

Update:
Measured DS angles and I’m “on the edge”. So improved the angle a bit using shims
—> shouldn’t be an issue moving forward

Pulled the DS, pulled the tail housing (again…), replaced bushing and sealing (again…)

Now my question goes to me output shaft.
With the housing off I have the following total play in my OS (total = full movement from one “side” to the other:
- longitudinal (forward/ backward): ~1-1.5 mm
- driver/ passenger: 4-4.5 mm
- up/ down: 4-4.5 mm

I also hear some “cluncks” when wiggling. I’m happy to share a video if someone is into transmissions. Send me a PM and we’ll get in touch.

Current idea: output shaft loose…
Would most probably cause serious work… Will see.

[Dearranged]

The driveshaft I ordered was supposed to show up today. Took mine out and did some measuring. Seems the one recommended in the catalog and the ordered part are different lengths, even though the correct length driveshaft is for a 6.0 diesel and mine is a V10.

So be careful if you go shopping for driveshafts and use the correct length as one of the criteria.

I'm hoping going from 3.5' to 4' dia will cure my high speed vibration.

What dia is your driveshaft?

[E-350]

Keeping my fingers crossed your DS fits!

I didn't measure it yesterday, but I strongly assume it's 4". On a junkyard some weeks back I saw thinner ones and therefore I just have an educated guess. But can measure tonight.

Status on my end:
Pulled the transmission, cleaned it up. Starting today with the disassembly.
Also opened another thread on the transmission itself.

[Dearranged]

What size are your tires? I see you geared to 4.56, that is going to spin your driveshaft faster except your larger tires will slow it down. I'm curious what your driveshaft is spinning. With your 5.4 I think ford used the 4" driveshaft but that would be helpful info also. You might be chasing two problems if the driveshaft goes out of harmonics and messes with the output shaft on the tranny.

[E-350]

Regeared my diff, not transmission. And I’m running 35’s.
But not sure how my diff/ tire changes driveshaft rpm at same engine rpm…

[boywonder]

...just tuning in to the this thread.....


Your pattern on your R&P is high (towards the crown) and towards the heel of the teeth as well. The pic is of the coast side. It appears your pinion isn't deep enough into the ring, ie you need more pinion shims.


Is the noise mostly when coasting?

[E-350]

Yes! Coasting around 55-ish down to 45/50-ish.

I’m right now doing the trans rebuild, just grabbed a forward sun gear from a junkyard. Around noon I get my rebuild kit.

Once everything is back in and noise still there I will check the diff again and go back to the shop.

Happy to hear more on the diff settings and touching points!

[boywonder]

There's a lot of space between the bottom of the contact pattern and the root of the tooth......The pinion is not engaged enough....plus you have heel contact.


Look at top heel contact on coast side in the chart below....I'd start by adding .005" shim to pinion. If you have a dial indicator and magnetic base it's really easy to check backlash.....on a Dana 60 I think it should be .006"-.010" or so. Your backlash may be correct; it's a pinion position issue.