The Stovebolt Site Forums The Parking Lot Tons 'o Fun 4:10 gear ratio

Hi Folks. I thought I would share some info I obtained looking for a 4:10 3rd member for my '51 1 ton Panel. I found a shop online called "Heave Chevy." 1-800-297-9694. The sell a ring & pinion 4:10 62-72 3/4 ton. This is worth a call.

If they have it, that is great news. By the way, the name is Heavy Chevy.

I checked their website & they're also listing the the 3.90 ratio gears which we'd all thought weren't being produced anymore. they're also showing a rebuild/bearing kit. here's a link:
http://www.heavychevy.com/html/rearend.html
the listing is for 62-72. I understood the Ho52/Ho72 3/4 & 1 ton axles to be the same from 47 through 72. I'm going to call them on Monday & check this out. that axle is one of the best ever produced, finding parts for it would be awsome.

i'm calling too!
been looking for a rearend for my 53 3/4 ton

To use the new gear set, you need to either make some modifications or put in a complete assembly from 67 to 72, so I understand. Someone posted about doing the modifications, a while ago.

3.90 gears would be nice in a 3/4 or 1 ton. I don't have much luck finding things with the search.

well swapping 67-72 pumpkin in my '50 housing is exactly what I did but the late & early pumpkins look exactly alike. even if they're not it would be worth finding a later third member & installing the more highway friendly gears. me & my truck both like 4.10s alot better than the 5.14s! I hauled about 1100 lbs. over the mountain Friday & it pulled it like it was nothin'. Denny Graham did this swap Awhile back & I'm almost positive he put 4.10 gears in his early 3rd member. I believe it was strictly bolt in.

So am I to understand the following...

1. That the axle tubes and center housing are the same from the 40's to '72.
2. The more desirable 67-72 center section (or pumpkin, or 3rd member)will bolt up in the earlier, said units without a kit/machining.
3. The ring and pinions mentioned from Heavy Chevy will only fit the 67-72 center section.
4. There is no (numerically lower)ring/pinion combos offered for trucks from 46-66

To wrap up...if you want a lower, numerical gear(those offered in Heavy Chevy)in your 46-66 Chevy; you have to swap out the center section from a 67-72, install the new gears and perhaps bearings, and then stuff that in you older axle housing?

Out of curiosity, what't their price on the 3.90 R&P set? Thanks.

$400 for R&P
$425 Bearing set

I believe the entire rear axle assembly (housing, axles & carrier/center section)for 3/4 & 1 ton is the same from 47-72. Ho52 designation for 3/4 ton, Ho72 for 1 ton. the only difference between Ho52 & 72 is the backing plates & brakes. Later model ring & pinions will fit in an earlier carrier. Denny Graham did it, he has it documented with pics http://www.pbase.com/dennygraham/eaton_ho52&page=all
If you find an entire 3rd member in good condition it's certainly easier to swap the whole thing. another reason I did it is because the ol' boy would only sell me the entire rear end anyway!

I've sent Heavy Chevy an email concerning this topic & a link to this thread. Haven't heard back from them. Anybody else talk to them?

i called a bunch a couple days ago
the phone goes to voicemail
we can only hope he's on vacation or even worse got hit by the tornados that went through there

You might want to read this article by Jim Carter Jim Carter Article

thanks truckernix
never could get them

rolf

i have read somewhere that the 4:10 came in trucks with an auto trans only. Did manual trans 3/4 and 1 ton trucks also come with 4:10 gears?

bozer - depending on year, the 3/4 ton will be about 4.57 standard and the 1 ton 5.14 .... the 4.10 [or 4.11] was in 1/2 tons with OD, otherwise the 1/2T had a 3.90

Bill

Chev and GMC used a 37-9 which is a 4.11 behind some of their automatics in the 60's, but they are getting very difficult to find.

Thanks Bill, I have a 50 ton. Need to find a pumpkin with highway gears to go in my housing.

It was the 67 to 72 3/4 Tons that had the 4.10 gear set, not the half ton. We are talking about a full floater rear end. My set is from a 1971 3/4 Ton. Some of them had a different style of rear end which is not compatible.

This is the truck that donated my 4.10 detroit locker.
http://i305.photobucket.com/albums/nn214/jfnar/57%20chevy%203800/70-1-ton.jpg
I don't remember if it was a 3/4 ton or 1 ton but it had a 9' long stepside bed that I took home with me also; minus the fire fighting equipment and water tank.

If I were searching for one of these I'd call every wrecking yard I know asking for 3/4 tons with automatic trans, that's where the 4:10s live. Suburban 3/4 tons had the harder to find 3:70 I belive. I found my set right here with a wanted ad, took a while but she's installed now. Also search Craig's list for a 3/4 ton parts truck, should be cheap. Most people would give away a blown up 3/4 ton of those years go get rid of the thing.
ADVERTISE!!!!!!

Thanks to all who replied. The search continues.

I did the swap last week. 4.10 locker from a 72 service fleet vehicle for a lumber company.
Filthy mess! the cover had been open for a while I guess but when I took it all apart I discovered it had brand new bearings all through it!
It was a quick swap, with the trickiest part getting the third member on and off the jack. a bit of juggling was involved.
I recommend doing the u joints while you are there. Mine were pretty rough and I found the yoke was twisted out of shape.
anyway the swap is simple and the noise level drops to acceptable levels in the cab!

Jeremy

I bought an NOS 4:10 from an axle specialist and to re-use my 3rd member all I supposedly need is a later bearing retainer on the pinion bearing, which he had.

Finally found a C-20 that should have the Eaton I need. Driving about 100 miles to pull either the complete rearend or just the center section. Any tips on what tools I will need. I have never pulled any gears.I would rather just pull the center section,if I can figure it out.

Suburbans had the same ratio options as the pickup.

bozer,
that pumpkin is quite heavy so be aware of that. I swapped out mine when the chassis was bare so I didn't have to work underneath.

14 bolts are about $150., most places.

Do the collective experts still understand that the only difference between the HO52 and HO72 is backing plates and brakes?

Also I found a thread on a different forum that indicated an outfit out in California sells the drums(Drums can be ordered from L and M Friction in Riverside Ca. 951-684-5713). I called and left a message. Has anyone else used 'em?

That thread also indicated that rear drums for a 70 Chevy K20 Suburban would fit. That sound right?

The HO52 and 72 differ in castings for center section. At least I've seen some relatively light looking ones and heavier ones with a screw to adjust and limit ring gear deflection under heavy load, presumably this is an HO52 and HO72 difference.
They will however interchange.

Brakes differ by vehicle model/size and also by years I believe. Brakes on a very late model HO 52 or 72 may be different than early model.

I'm not aware of an available direct replacement for just the drum on an AD 1 ton rear. Please post your findings.

As discussed in other threads and other forums you can swap and update the entire brake package on the old Eaton for brakes from a 14 bolt or aftermarket brackets and disc brakes, or make your own brackets and use very late model disc with park brakes (I'm doing this one).
But, at some point an entire 14 bolt is cheaper and easier, and easier to get any parts for down the road. Why swap gears and brakes on the old axle when the correct 14 bolt with those upgrades can be installed whole? (I'm also swapping in a 14 bolt)
Plenty to consider.

Don't forget guys, GM 14 bolt ff rears come in dual and single wheel versions, some with disc brakes, are laying all over in yards, lots of modern ratios, cheap($150. Usually) , easy to change R & P. I see lots of people spending lots of time and $ trying to find higher gears for original axles when a 14 bolt would do the job, relatively inexpensively.

Ed

I will second that Ed.

I have one in my garage if anyone is looking...

And the 14 bolt duals come in full width and cab and chassis.

The cab and chassis 14 bolt axle width is same as AD 1 tons, both the single and dual wheel version of our old trucks.

Point is well taken fellas. It is very good to have the option. Besides A/C (Texas heat) and a brake booster I am really trying to go back with the same equipment that would have come on her from the factory (and 4.10 gears and a 12 volt system). OK, I'm a hypocrite. If it comes down to $1000 difference to end up with a safe rebuilt RE (HO52 vs 14 bolt), I'll have to add this to the list.

There's nothing at all wrong with the Eaton axle. However depending on condition of what you have and what you want the 14 bolt may or may not be easier and cheaper.

For example, you have an Eaton axle and want but don't have 4:10, and you need entirely new brake parts, particularly the drums. Then you should look closely at moving on to a 14 bolt with those gears readily available and all new brake parts on the shelf at about every auto parts store. This is more involved to swap, but doable.

Or you have an Eaton axle with recently checked out and overhauled brakes in good order. You don't have 4:10 gears but want them. Then I'd keep looking and find that 4:10 center section to swap in. It's a quick and easy swap once you find the used center section with the right gears.

I'd like to piggyback on to this post with a question about a 14 bolt. I recently purchased a '57 GMC one ton panel. It has a non-original Dana 60 4.10 that is a little too wide. It measures 65.5" wms-wms. I put 255/85R16 tires on 16x7 eight lug rims that are about 1" wider than the stock 17.5" bias plies. The tires are too close to the wheel well lip for my comfort.

I measured a spare Eaton HO52 that I have. It measures about 62.5" wms-wms. I know the Eatons were on Chevy's and Spicers were on GMC's, but the width should have been the same.

The extra 1.5" width of the axle on each side plus the extra 1" from the tires has pushed the outer edge of the tires out almost too far for the wheel wells. There is plenty of room inside the wheel wells. I'll be good if I can install a rear end the same width as the Eaton because I'll pick up 1.5" on each side.

I found a 14 bolt 3.73 posi at a local yard off a '94 3/4 ton Suburban. It is 65.5" wide, so it would give me the same problem as the existing Dana 60.

I want to stay with 8 lug rims and a full float rear end, so I don't want to swap out for a 1/2 ton rear end.

I need a narrower axle. I can easily install my spare 4.10 Eaton, but I really want taller gears. I don't want to narrow the existing Dana 60. Does anyone know if a version of the 14 bolt was available in about a 62.5" wms-wms width similar to the Eaton?

Thanks,

Matt

From a few post up

This is 62.5" plus or minus a small fraction.

Found this that explains the different 14 bolt configurations:

https://roundforge.com/content/article/A2WJF75B/14-bolt-axles-the-difference-between-srw-drw-and-cc/