4.10 to 3.55 swap for $85 -- worth it? (Rear only)

[raydav]

ZF5

So your top gear is about the same as mine. 3.55 works fine here.

 

[pcpotter1023]

I have a 1991 F250 IDI non turbo with 3:55 gears and when I put a trailer behind it it knows the trailer is back there I pull a dump trailer (14K loaded) from time to time short distance and it REALLY knows when that's behind it. I know this isn't a good comparison because of the non turbo also I got SORRY fuel milagee with a trailer again though mine's non turbo

 

[austin92]

I may be way off here but when I get to playing with gear ratio charts I look to see if I can still grab 4th at minimum 80mph. I plan to run 33s on my 88 (when I get around to that project), right now it has 3.54s and I think I’d be happy with 4.10s but I’ve considered 4.30s. If I was rich I’d run 5.13s and a gear vendors My beliefs here; the lower axle gears relieves stress off everything from the pinion forward. Idk, just rambling... lol


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[Isaac Ristow]

I may be way off here but when I get to playing with gear ratio charts I look to see if I can still grab 4th at minimum 80mph. I plan to run 33s on my 88 (when I get around to that project), right now it has 3.54s and I think I’d be happy with 4.10s but I’ve considered 4.30s. If I was rich I’d run 5.13s and a gear vendors My beliefs here; the lower axle gears relieves stress off everything from the pinion forward. Idk, just rambling... lol


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agreed about less stress other than the motor has to crank out more rpm but less load but thats fine they like rpm better than lugging. doing the same ratio swap myself 3.54 to 4.10

 

[The_Josh_Bear]

Ok so mister $85 axle flaked out. Found a $100 axle up north, not listed as a locker or anything.

What the hell am I looking at??

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PS I cant rotate it because the right brake drum is all seized up and whatever this is let me rotate it enough to verify its 3.55, but then the fun stopped, lol!

 

[david85]

Looks like a Detroit locker. Not a bad score for 1 bill...

https://www.drivetrainshop.com/Detroit_Locker_p/eat-225sl56a.htm

Scroll down to see another view of it here:

https://www.ford-trucks.com/forums/1201508-10-25-sterling-detroit-locker-diy.html

 

[The_Josh_Bear]

Yes sir it sure does! Brand new gears too, or at least ZERO wear on them. Wow, nearly $1,000 just in parts for that setup!

I've heard they are clunky on the street buy quiet down after a while... but hey I'll run it and see how it goes. Woot! I never get cool scores like this. Thank God for totally random car parts that rock!

 

[The_Josh_Bear]

Update:

So I posted in "So what did you do to your truck today?" That I installed this axle. I didn't have the front to match but(when I started) there had been no snow this year and it was unseasonably warm most of January. By the time I had the axle installed there was 9 inches of snow and then it was time to fix the brakes! They were absolutely nasty and I had to replace every piece of hardware to the tune of $315. BUT it stops great and is very predictable, better than my other axle.

Also as planned I got the rear axle first... and so the front is still 4.10.

I have to say the Detroit is pretty darn awesome! I don't have a lot of miles on it in normal situations because of the snow, but I'm really liking it so far. It's extremely predictable and really digs in hard compared to an open diff. But without a bunch of weight in the back and due to the 4,000lbs over the front axle(yay IDI!) you can still get stuck on nearly flat ground if you dont keep your speed up.

So I have actually had to use my 4x4 at times in snow even with the mixed gearing. It's no fun but gets the job done! The rear end spinning faster plus the locker makes it real squirrely but it pulls like crazy when you hammer down. Wow. And I have not great tires up front.

So that's the update, now a question:
Is this the right ring and pinion for my D50 front?
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/371687663327

There's also a brand new Spicer set for not much more:
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/362537466733

Thanks oilburners!
-Joshua

 

[Clb]

The t case is gunna H8te you...
Let's hope it spits a u joint first.

Wait till the Detroit unloads in a tight spot/turn it's gunna sound like a bolt snapped in two.
Nothing will be the matter just the nature of the beast.
I have a set in the crawler ,they work good, still wanting to put in arb'$$$.

 

[The_Josh_Bear]

The t case is gunna H8te you...
Let's hope it spits a u joint first.

Wait till the Detroit unloads in a tight spot/turn it's gunna sound like a bolt snapped in two.
Nothing will be the matter just the nature of the beast.
I have a set in the crawler ,they work good, still wanting to put in arb'$$$.

Thanks for the advice! I'm deliberately only running 4x4 when I'm on snow with no traction so I don't break anything. And I mean just a few seconds usually and I think I was doing it about 2 mins on the freeway up a fairly steep grade the other day but thats it.
I hope my tcase is ok through it all, I need that.