The Stovebolt Site Forums The Parking Lot Big Bolts Eaton 2 speed 17201, 17221

I need some help.
I bought a rear end and it was supposed to be a Eaton 19050T. Come to find out after the fact that it is a "17200" rear.

Did a little looking but found VERY little on these rear ends. I did find out that it is either a 17201 or a 17221 (not sure of the difference, won't know for sure until it arrives which one it is).

But there seems to be almost nothing on these rear ends on the web. How can that be?
Any help on this would be appreciated.

I'd like to start with some basics like ratings and measurements.

Thanks.

I expect there's info out there just not to be found under the "proper" model number. Do you know any other distinguishing features or nicknames for those guys that might help in your searches? Can you find anything in the service and parts manuals for the trucks they were installed in?

I have a hollander for the Eaton rearends, copyright 1974. The first two numbers give the capacity, in your case 17 equals 18,000 lb early or 18,500lb late. The 3rd and 4th number is the design type. The 5th number is the brake type, yours should be air brake equipped if I understand the book correctly. It lists the 17201 and 17221 as the conical(smooth, not ribbed) carrier. Has lots of gears available, ranging from 3.70/5.05 to 7.60/10.36. I have all the part numbers here and gear codes if you can get them from the pinion. Let me know if I can help answer any questions. The book does not give dimensions, however.

The 17200 series was probably produced until 1989 or so. Here is a bit of information from the Eaton website.
http://www.dana.com/wps/wcm/connect...iveAxlesServiceManual_LR.pdf?MOD=AJPERES

Page 4 refers to model numbers.

Hy journeyman, 17201 and 17221 are spiral bevel differentials, I have an overhaul manual if you need specifics, hope that helps.

3B, take a look at the Eaton website, page 4. The 17201 and 17221 were what is referred to as the old style, but they were hypoid, not spiral bevel.

OK. Thanks all... This is great.
I have seen the Dana PDF, which gives some good adjusting/rebuild info, but I am looking for some really basic stuff to start with, like the difference between the 201 and the 221, load ratings, etc.
Possibly the intro to the overhaul man. or the specs section might have something?

Also, how were the "early" axle models different from the late model axles? Is one preferable over the other? Were there design improvements?

OK, but why does "17" = 18,000 Lbs? and by early/late what do you mean? I thought all the 17 series were early.
And do the 17201 and the 221 have the same weight/torque ratings? Just different brakes?
I have the 4.11/5.63 ratio with hydraulic disk brakes. Brakes were most certainly a change out. I have no idea what was on it originally.

Well, I am not sure why 17 equals an 18k lb capacity but here is how the book breaks it down.

13=10k to 15k (varies with year and housing)
16=16k early, 17k late
17=18k early, 18.5k late
18=21k early, 22k late
19=22k early, 23k late
20=23k
22=29k

As far as early/late the only 17 series rear I see that it pertains to is the 17500-01, the early version has 2.125 inch spline axle, late version is 1.97 inch spline. I have a 52 GMC and it has the 1.97 spline. It does not state an early/late transition year.

I used 2 speeds until the early 80's and all we had was the early style. The early and late that Eaton books refer to was due to the a change in the shifter box. The early used a motor that reversed by reversing polarity and they had points in the box to stop the motor when the shift was completed. An ajax screw controlled the shift lever. They were simple and worked well. But in daily use, water would get into the box and the points would corrode, the ajax screw would gall and the bottom bearing would fail. Sometime in the late 80's, Eaton introduced a new style, that used electronic circuitry which was supposed to be better. I have never owned the new style. The old and new style are wired differently, the motors and none of that stuff is interchangeable, but Eaton did sell a unit to upgrade from the old style to the new style. This didn't interest me because already in the late 60's I had decided air was a much better way to shift a 2 speed.
The 1700 series was the most popular in those days. It was rated at 18,000 and no one knew why. 18k was all most states allowed on a single axle in those days. The 20 series was used in higher horsepower applications.

I finally got to getting everything separated and apart.
Here is what I see:

Casting marks on differential: 67757
E229
Stamped on differential:
C1979
4911
72944

My guess is that it was mfg'd in 1979, but beyond that, no clue what the rest of this stuff means.

67757 comes up as part number for the carrier

72944=4.11

E229 I believe is the date code, but my book is 74 and doesn't give the code for yours

4911, this may be the ratio also, are you sure about the 9, book shows a letter in the 2nd position

C1979, not sure on this one. My book is 74 and your rear is possibly newer than that.

So, its an 18k lb rear with 4.11 high. Is it useable to you now that you have some basic info?

Useable? Yep. Always was.
I just like to know as much about what I am getting into (and investing my $$ and time in) before I get too far down the road.

This was supposed to be a 19050T, but maybe this will do just fine.

Did you buy just the third member or the entire rear end? If you bought just the third member, you need to see if it will fit your banjo housing. There is nothing wrong with the 17200 series. I ran them for many miles years ago. In my opinion, I would prefer the old style shift box because it is much simpler. You can see whats going on inside the box. What year truck are you working with?

I got the whole axle and suspension.
It was out of a 02 C6500 but the axle got switched out.
This project is a later model... I'm asking here because this group seems to be one of the few that actually knows stuff beyond what is listed in the standard replacement pages of the parts store.

Soon (I hope) I will have a 10 on 7.25" bolt pattern disk brake rear end for sale. It has a 4.6 ratio (4.66? 4.62?) and I have gray powder coated 19.5 duals for it.

Kenneth, is there any reason I could not use the third member from one of these 17200 series rears in my old 52 gmc 17501 housing. The hollander shows they use the same gasket(3rd member to housing) so the bolt pattern is the same. It also uses the same side gears so it should mate up with my original axles. Am I missing anything. I need a third member anyway and this 17200 series has a lot of gear options available. It looks like the 17800 has the same gearing options as the 17200. Any thoughts?

We used to interchange the entire 1700 series. If it came from a Ford or IH it could have different side gears, but you have already checked the side gears. What you are doing worked 50 years ago and should still work. My concern was that Journeyman was going to try to put a 1700 series in a late model housing. I'm not sure if that would work because I am not familiar with the later model 2 speeds.

Actually, for me it was a late model 'rear clip' (frame cut off) with the entire axle swapped out.

From what I have seen (and I am still a novice at this), as long as you have the same bolt pattern on the pumpkin, same ring gear diameter and same axle splines, you should be able to swap from a single speed to a two speed differential. I have seen these listed on the truck sites (LKQ, etc.) for as low as $495, with a variety of ratios, usually in the 6.50/8.90 or 7.17/9.82 range, but there are some high speed ratios like I got in the 4.11/5.63 area.

There is one more thing that could be different. These heavier rears have locators to support the back side of the third member. We call them dogs. I'm not so sure I would trust anything from the LKQ web site. LKQ is an investment group that bought a bunch of salvage yards and are closing them now because they don't know the salvage business. In fact I bought a trailer load of Merritor rears at their closing auction at West Monroe, LA back in December. I would call someone who has been in the salvage business all their lives. Possibly someone like Doug Geiger at Geiger Truck Salvage in Watseka, IL or Rod Thompson at Thompson Motors in Wykoff, MN. These guys have been doing salvage all their lives and don't need books.

Journeyman, how many bolts or nuts/studs attaching the axle to the hub on your rear, my 17501 has 12. Just wondering if that is an easy way to spot a 17 series in the junkyard?

Looks like 10 bolts. I am not there in person, so going off pics I have. I'm pretty sure it's 10.
I wish I could post a pic...

The 1700 series was used in the GMC 500 or 5000 series, Chev 70 and 80 series Ford 700 Series. However, lighter rear ends were retrofitted in 2 tons quite often. Any 50's through 80's of around 3 tons is a good possibility and electric shift is a good indication.

I have a '51 GMC 620 with an Eaton 2-speed vacuum shift. The code on the axle says S-7544, which is not specified in my manual for this truck.

In any case, I'm wondering if there is an electric shifter to replace the diaphragm which pulls on a crank which shifts the unit. I no longer have the air shift control valve that controls this thing, so I'm stuck in low range.

Thanks for the help.

Day Radebaugh

I think a metal plate can be made and installed to prevent it from shifting out of high. There was a member here that did that. Don't remember who. Maybe someone will. Jefrey

Yes, I think I can always rig it so that it stays in high. Know of an electric replacement for the vacuum unit?

No I do not. Jeffrey

Jefrey, do you mean a plate that would not allow the use of low range, or do you mean a plate that keeps it in high range only when shifted in "high" and still allows low range use?


I built a 'dummy motor' that will hold it in high range, but I really need the use of both ranges for driving.