Best sources for rear end

[HolyBus]

Lets talk rear ends (punkins).
If I am looking for a different rear end ratio, what vehicles can I pull a punkin from and use in my bus? I have a 88 IH front engine long bus. The rear is currently 5.38 and I could use something a little better for the highway speed. Nothing exciting. What vehicles can I look at that might have what I need? How do I know if it will bolt in? Dump trucks, semis, what?

thanks

[onenationundergoat]

I see you've started a thread on this. I'm not sure if ours are compatible or not, but if they are and you manage to find a better one, I'd be interested in your 5.38

[Kubla]

first you need to find out which axle you have in the rear, then you can search Ebay for the right differential for your rear end, they are not interchangeable between different series rear ends, also you can do a google search for your specific (for me spicer N190) differential as there are many truck salvage yards out there selling them

[Kubla]

Yay!! Got my 4.10 differential today, now to get it and the MT643 installed. Then find someone to buy the perfectly good AT545 and 4.78 rear

[onenationundergoat]

How much for the rear end? I went to a junk yard today looking and couldn't find one.

[claydbal]

best source for rear end i have found is match.com. various ratios and hold lots of torque.

texas is the preferred state.

[nat_ster]

Originally Posted by claydbal

best source for rear end i have found is match.com. various ratios and hold lots of torque.

texas is the preferred state.

That's funny. I was thinking the same thing.

Nat

[EastCoastCB]

The title did give me a chuckle too.

[Dragonpop]

Try this web site www.heavytruckparts.net or just google medium duty truck parts and salvage. Why would you want to change out the differential? My bus has 5.38 gears and with the Allison MD3060 it does 1800 rpm at 60 mph in 5th gear I would change the transmission first rather than the differential.

[Hvbuzz]

I have gone with a 4:10 for my bus also. I think Kubla is right. I already have a spicer 6+1 which is 1-1 on the top end, just like a MT643. With 11r22.5 tires I figure that will put it a good cruising speed of 68mph. The MD3060 is a nice trans, but I think it would be a very expensive swap into an older mech diesel. I keep hearing people talk about it, but I would like to see it done and how much $$ it cost to do it.

[Kubla]

I got my differential from
MICHIGAN TRUCK PARTS
Ph: (734) 722-3800
Fax: (734) 729-2363
38658 Ford Rd.
Westland, Mi 48185
had to do a few google searches to find it and one close enough to pickup since shipping would be at least 200 dollars

[jazty]

How were the prices and service at Michigan Truck Parts? I'm often down in that area and am looking for a locking diff. They may be an option..

[Kubla]

I paid 495 plus 100 core charge (old one is still in the bus) so $630 with tax, pretty easy to deal with

[jazty]

Excellent! That's a very reasonable price. I've seen some prices online upwards of $1000.

[Jolly Roger]

I have an 86 Wayne with the 8.2, at-545 , and an eaton rear with 6.50 gear's and can't get any local garages or mechanic's to give me advice on what gear's to change to? The older man at the bus barn that sold it to me said I could adjust the governors but I would burn up the rear end but he was not allowed to tell me anymore.
I can only do 45-49 right now and would love to do 55-65. I can and am willing to do any changes myself but no one will recommend a ratio for me to change to? I have all info including full maitenance record's from the school system including all data plates.
Thank's for any advice.

[Kubla]

with a 4.78 rear end, 10R-22.5 tires and a AT545 transmission, my bus does 62 mph at 2700 rpm, if it had a lock up torque converter eliminating transmission slippage, it would do 68 mph. 2700 rpm is pretty much max speed for the engine, a DT466

you need to find out exactly which rear end you have to buy another differential, adjusting the governors for more engine speed would most likely burn up the engine, not the rear end

[nat_ster]

Mine had a 5.9 Cummins, 4.44 rear end gears, and a AT545.

2500 RPM at 62 mph or 100kmh.

Poor engine hated it as the torque curve drops after 1600 RPM.

Nat

[Jolly Roger]

Thank's for the advice! The bus barn man was speaking from the advice he had given his church for the bus's they had bought and they did one as advised with no problem's but they didn't do the next two and have constant problem's?
I am looking for option's cause I can only afford to do this once or the other main project's that require money are going to suffer? The rear end is eaton model 16s and the original bus barn document's say 6.50 gear's with an at-545 and an 8.2 non turbo and 9r20 tires.
The only other thing I don't like is that whether on flat ground or uphill the tranny shift's through the gear's and you are in drive before you ever get past 20 mph? I still have not removed the blocker plate on the shifter but I am ready to! Then I can manually stretch each gear more before it shift's? That would help with low end but top end is what it is until I change something?
Thank's for the help gentlemen.

[frank-id]

Most heavy axles can be interchanged. Most axles are about the same size. My Crown needed a different ratio axle. I got a 1990 freightliner axle for $1200. Everything was good. Got newer gears, correct ratio.. 3:73, bigger brakes, newer slack adjusters and very good unit.. Frank

[maloiselle]

Recent differential swap 3-30-2015.

1999 Bluebird 3800 9 window
DT466E
MT643
N175 Rear w/4:78
255/75R 22.5
55 MPH @ 2500 RPM

Swap to 3:54
65 MPH @ 2300
75 MPH @ 2500

Cost $550 +$150 core
VanderHaags Inc.

Easy Swap like a Ford 9", just bigger.