so on the other thread "rear diff oil options" lead me up to a point where a mechanic was telling me my rear end is getting bad. It began with a strange vibration- and we found a dead U joint. While it was in the shop for the u joint I had them take off the cover and have a look inside the differential.

He said there's too much play in the spider gears, the big fat pin, and pinion assembly. I saw some free play but I didn't think it was excessive, nor worse than I've seen on a few dozen differentials in my life. Anyway he wasn't giving me a hard-sell, and the shop owner is an acquaintance that I trust.

After replacing both u joints the vibration is mostly gone. Still a little something upon deceleration though. This makes me think maybe he's right about the gearbox internals.

So im stuck in this situation with two sets of questions:
1. Is a new/reman unit very expensive? Or get this rebuilt? Or just get a $300 unit from a junk yard? I will NOT be doing the labor due to my bad back. But I know some wrenches that'll do it for cash.

2. I have 3.73 now- and if I'm changing rear end I might as well get an upgrade on ratio for more towing power. 4.10 could be cheapest since it's probably available on the junk yard racks, ready to bolt in. But I like the motto "go big or go home" so I'm also considering going bigger like 4.30 or even more. Because this van will be semi-retired in the next six months and will only be used for towing a few times per month.

2. Back to my question lol: is there a way to correct my speedometer without an expensive tuner? And question 2b: if I leave the speedometer INcorrect after changing gears, will that affect the ABS or anything else on the van? (Besides the speedometer and odometer)

thanks everyone.

 

Well I posted some info in your other post. This is how you change the spider gears in a 8.8. i don't know how much different the dana 60 is but this is pretty simple.

I have back problems too so I do the research on ow to do it and then get a neighbor to help out with the heavy work.

If you search around you might find a video on how to do it on a Dana 60.

 

Thanks annaleigh I'll watch the video later today.

I'm still hoping for more answers to my questions above as well.

 

4.10 should be fine , anything bigger your just burning gas.

Check the web for differental prices , I would buy new . Do it right do it once.

Call a ford dealer for info on speedo adjustments, you may have to have them do it .

 

I'm not sure I'd be so thrilled about just replacing the spider gears. If you're doing that you're going to at least want to change the side gears and probably whatever pins and bearings locate them as well. And if the differential has worn, are there metal filings in the gear oil that have been working over your ring and pinion? If it was me I'd let a good shop go in and see what needed to be done and do it right, but I wouldn't try to patch together the current diff on the cheap.

A replacement axle from a junk yard is a low cost option I might consider, but there's no guarantee that it's in much better shape. So if it were me I'd probably see this as an opportunity to upgrade to a TrueTrac limited slip. The parts cost would probably be a little more expensive than rebuilding your current diff, and the labor would definitely be more (but no different if you are also replacing the ring and pinion).

I don't have a ton of experience with the Triton engines (I'm assuming from your avatar you have the V10), but what little I have says that they like to rev. I had a 5.4L in a 2008 F-250 with (I think) 3.73 gears (possibly 3.55?). That was a total dog. Now I have an E-450 motorhome with 4.56 gears. That screams a little. If you don't mind the sound of the engine, especially if it'll mainly be used for towing, I think your thought of 4.30, or even 4.56 gears is a good plan. And by the way, if you take your trans out of overdrive (assuming you can, I can't in my motorhome), direct drive with your 3.73 gears would be the equivalent of about 5.25 gears in overdrive (assuming 0.71:1 overdrive, which is what my '97 E4OD and my '15 5R110W both have). So if you can tolerate that engine noise, 4.56 gears would be about the same at about 10 mph faster.

I don't know about newer trucks, but back in the '90s the rear end ratio didn't affect speedo calibration. The speed sensor was on the rear axle, downstream of the ring and pinion, so the tone wheel it was reading was still going the same speed. I don't know for sure but I'd guess your van's speed sensor is also on the axle, so no recalibration would be needed.

Changing tire sizes still requires recalibration, and the '90s trucks could be recalibrated at home with no tools. I don't know the step-by-steps (I'm sure you could Google it though), and I don't know if Ford kept that feature as the years went on, but it seems like something they'd keep.

 

Since you said you would update the other thread, I thought I would just copy this here and reply so you have 1 thread going on.
Well i have not had good luck with shops around here. I took my GMC to a well established and reputable transmission shop that also rebuilt rear ends. My GMC had a bad bearing in the rear axle somewhere so the mechanic rebuilt it. When I picked it up there was a grinding noise from the rear axle as I was pulling out of his shop. He said, OH I know what it is and took it back in the bay and tightened the pinion yoke nut. Well back then I had changed out axle bearings and seals but knew little about differentials and so assumed he did what he needed to.

WEll about a month or so later the differential developed a roaring sound and when i took it back he told me that he had used axle saver bearings so I wouldn't need to buy anew axle. Apparently the axle shaft was too far gone and the axle had chewed up the new bearing, more expense..
Shortly after I traded the GMC for my Ford van.

Now, though I am not a pro, but do know much more about differentials, I know you don't just tighten a pinion nut and send the car dawn the road. I know you have to set the pinion depth and then pinion bearing preload. Once that is done you do not remove the pinion nut again!. So then why was it loose to start with?

SO my thoughts are if I am going to pay good money to get crappy work, the I will learn how to do it myself. That is part of the reason why I mentioned in another thread about swapping the 9" out of my 85 into my 88. On the 9" one can buy a complete third member already set up and swap it yourself for about a third the price a shop charges to rebuild one. On the 9" you just pull the axles and the differential just unbolts from the housing all in one complete unit. I already did that once on my 85 to clean out the axle housing while changing the axle bearing and seals.

I understand your concern about setting the differential up correctly and at one point I would have been more confidant rebuilding an engine then a differential but I have been thinking about this for over year now and researching, reading, and watching videos off and on till I am just about ready to give it a shot myself. As my father was also a machinist and taught me a good bit as he always made any parts we needed to fix something, I have all the micks and gauges needed to set one up and know how to use them. It doesn't seem so intimidating any more.

This is an example of a bad axle bearing race from my 9" axle




Here is the housing after I cleaned it up inside and ready to reinstall the differential


So I am not afraid to jump in there and do it in the future... I know there is a big difference in cleaning parts and setting up a differential

 

Sounds good annaleigh !

I think you're the perfect person to do this yourself. Plus if I remember correctly your life situation is such that you won't be hurt by an out of service van. In case it isn't successful on the first try. (Like it would be for my attempts).

Please make a new thread when you do it. I personally want to see.

 

4.10 if I get a used rearend.
If I buy new stuff I'm going with 4.56


go big or go home

 

Thanks for the well wishes Im50fast!

Yes unlike you, I can do without my fan for week or so, so I have the advantage of taking my time to get it back together right. Your down time is money so you have to figure out the best corse of action to meet your needs.

You are really in a hard position right now since you are planing on buying a newer van in the near future. If you buy a used axle there will be the instalation cost added to it and then like Nothing Special said, you wont know the condition till you install it and perhaps run it for a while. If you had to swap it out for some reason or just have all the seals replaced, now you are pushing towards a rebuilt price.

If you rebuild yours, now you sink a couple of grand into a van you want to semi retire that may have transmission problems in the future.

What shape is the engine in? That v10 is supposed to be fantastic engine if you keep up the maintenance. Do you think you can get another 100k out of it? Have you thought about rebuilding the rear end and later the transmission when needed? That might get you another 100k or more for around 4 or 5k...

Iwill start a thread if I find I need to rebuild mine.. If you rebuild yours, let us know how much it cost and what they replace.

 

I’m having mixed feelings about the rear end being bad or not.
Immediately after getting the u joints replaced the van was much improved- no more scary vibration/droning. There was a slight vibration/drone but it is drastically reduced from before.
FYI I know the u joint was bad: I saw the technician put his hands on it and it moved about 1/4” up and down.

But since then... some vibration as just mentioned, but NO issues pulling the 7,000lb enclosed trailer. And let me tell you I hooked up and drove away carefully.
Drove it home 50 miles highway, then around town 45 miles to the event. Then back to storage 50 miles highway. And NO noticeable issues with towing.

Im skeptical about the rear end issue. I feel like a 6,500lb vehicle pulling a 7,000lb trailer woulda/coulda exacerbated the problem, or maybe even obliterated a rear end with excessive wear.
What do you all think?

 

well I can understand your skepticism. Just like mine having a vibration, I am thinking on no when it could just be the drive shaft needing balanced..

Its a bit late now but it would have been nice if you could have been there and actually checked for play on the pinion shaft yourself while they had the rear cover off and the drive shaft loose from the yoke. That was the prefect time to feel of the bearings and for sloop in the pinion shaft...
How does it do empty without a trailer? Any difference pulling verse coasting?

The way I understand it is say the pinion bearings are just a "little bad" (humm), when you are pulling it kind of tightens things up and depending on the severity, you may not hear or feel anything anything. When coasting though, everything is loose and you will notice the vibration a bit more.

Its just one of those things you are going to have to make the call on. Keep a good eye/ear on it and if anything changes, get a second opinion.

 

i did see it with the diff cover removed. And they showed me the backlash by turning it back and forth and said “see? That’s bad. You need spider gears and pin right away. And start saving your money now for a full rebuild or replacement”.

But when I watched the display of backlash, I wasn’t feeling it.
All my life’s knowledge of automobiles is a bit outdated but I don’t think ring/pinion backlash has probably changed much. I am a numbers guy- I want to see a dial indicator on there. But instead I just saw “a little bit”. To be clear- what I saw matched perfectly to what I believe to be OK. But obviously lots of room for error in my judgment there.

and of course the remaining vibration/droning afterwards. Much much improved, but ...
It is only/mostly just when coasting, though intermittently at steady light throttle.

Another experienced technician i trust said “rearends don’t just blow up and leave you stranded, so just go on with your life. It will start howling and vibrating and die slowly, giving you plenty of time to act.”

 

BS. There are numerous ways for them to break.

 

I've done a number of junkyard rear end jobs from swapping the 9" Ford pumpkin to a full axle swap. All went well and the swapped rear lasted because I didn't just pick something off a shelf at a yard, I went and found a lowish mileage one and cleaned it out before install.

FWIW I'd rather swap a full axle than swap gears - I know I'm ignorant about what needs to be aligned and how, and replacing a stock axle is a lot less technical.

 

With all due respect, that "technician" isn't all that "experienced" - Any bearing in the rear can just go over the line and melt or take something else with it and you'll be stuck on the side of the road. Been there, done that, got the t-shirt.

All you need is the roll-pin holding the spider-gear pin in place to shear off, and you're done.

Like you, I want to see a dial-gauge on the ring gear to see what the backlash is.