cracked rear tailhouse Ford E350 - Page 2

keytothestone · 05-15-2019, 01:26 PM

Michael thanks. Gave the shop a call and asked them to look into the mounts and the Ujoints. Really surprised they didn't bring up those possibilities when they were showing me the DS bounce. Come to think of it not really that surprised. Thanks for your input, and will keep things posted.

arctictraveller · 05-15-2019, 01:32 PM

Quote:

Originally Posted by mgmetalworks

Those mounts can go bad. I'd replace that part because it looks like excessive bounce on that mount.

That was my first thought too. It should be pretty easy to see what's actually moving by having someone move the transfer case around and watching closely in the area of the mount and cross member. Be sure to have a look at the other mounts too while it's being moved around.

keytothestone · 05-22-2019, 10:50 AM

update. Got the van back. Trans mounts are all good ujoints all good. Put on new tail house. Got under the van with the main mechanic. Drive shaft and Tcase still have a lot of play. The cross-member UJ put on during the conversion has a lot flex especially on the extended plate where the trans mount is. In Jeffs opinion @ Built to Last in Dgo. the cross-member is placed to far back towards the rear to give room for the MG radius arms and the cross-member shouldn't have that much flex. Most stock E/F-series the cross-member and mount are a little more forward. Also that the 4R75W trans and the small TH and well known week TH with the huge NV271 Tcase is not a great match & needs much better support or this is just going to happen again in the future. They won't even warranty it! He's suggesting fabricating a new support around the radius arms and I'm currently thinking of moving on.

Vanzila · 05-23-2019, 09:59 AM

Nope not common my 4x4 Econoline is going on 24 years old now.. you may have and issue with pinion angle to the rear axle putting to much stress on the Tail shaft.. Who / What 4x4 conversion is yours .. ?

keytothestone · 05-23-2019, 10:04 AM

MG coil installed by UJ

E350 · 05-23-2019, 10:12 AM

Anything that long is going to flex. Period. And that includes a rear driveshaft.

IIRC, the F-Series 4x4 SuperDuty rear driveshaft came either as a one piece or as a two piece. A two piece drive shaft with a center support would IMHO reduce the flexing. Installing a regular Yoke off the transfer case tail piece instead of a slip yoke off the transfer case would reduce the likelihood of leaks at the rear of the transfer case. The drive shaft slip joint would then be at the center support for the two piece drive shaft.

Like in my Bronco.

I am contemplating doing something like the above for my van.

IMHO you have to be as knowledgeable as the converter about your conversion to be a happy camper. I relied on Salem Kroger for my conversion and eventually became dissatisfied. I could do it now myself or have it done to my specification and would likely be more happy and would have saved money. At the very least I could discuss the various pros and cons of conversion design intelligently with the converter.

Bottom Line: You are redesigning a vehicle. We all need to take ownership of that fact and study up to the task.

Trevor · 05-23-2019, 11:32 AM

Just a piece of info that probably won't help the original poster here, but could be interesting to someone else... when I converted my 4R100 trans I was able to find 4x4 tail housings in both steel and aluminum. I opted for steel as they were the same price used, but due to a mixup I received both in the mail.... giving me a chance to compare them. I'm guessing the aluminum 4R100 housing might already be stronger than the 4R75W and there may not be steel housings for 4R75Ws, but for someone starting a conversion from scratch I wonder if a transmission swap would be feasible just to address this problem. Or maybe it's rare enough to not warrant the cost and trouble.

keytothestone · 05-23-2019, 01:40 PM

E350. ..thanks for the response. If you view the video previously posted I would say that is more than just a flex. I got under a 04 SMB quig conv. And a F350 yesterday. Absolutely no flex no budge nothing but stout and solid. And my mechanic, MG, and Chris @ UJ all agree this kinda movement is not normal. I will bring up the pinion angle & yokes. I just dropped off the van again while I head home for a couple weeks to have them replace a lower front ball joint that's thread is stripped somehow? ??? And check out other potential issues. And hopefully can come up with solution to this current one.

E350 · 05-23-2019, 01:59 PM

Yes, I see from your video that the transfer case and the transmission are both moving up and down with the drive shaft.

Since you are moving both their weight and possibly the weight of the back of the engine since they all should be bolted together and thus moving up and down in unison when you are pushing up. Dang you must be one strong guy!

Something is not mounted. Videos and/or pictures of the mounts on the back of your engine and/or under your transmission and/or under your transfer case would be helpful.

One thing is sure. You will find the problem. It has to be obvious to have that much flex!

mgmetalworks · 05-23-2019, 03:17 PM

I asked before if the cross member is flexing. I couldn't tell from the video. If it is, get rid of it. It is not up to the task and looking at the design, I can tell it has some weak spots. You may even have a crack somewhere that you're not seeing.

I've modified V10/Diesel factory cross members (for use in V8 rigs) and had no significant flex, nothing more than a stock Fseries.

It isn't a problem to have the cross member where it is if the cross member is built to handle it. You can also go the route of moving the cross member forward if you want to spend the time and money to do so but I think it is less work to modify one from a V10/Diesel.