I should have listened to you guys...6 lug to 5 lug conversion

[par4tom]

My 61 chevy truck has a rear end from a 66 or 67 chevy truck in it and it is a 6-lug. The number on the differential is HC 8 06w. I believe (and check me if I'm wrong), this is a 3.73 Posi unit manufactured in August of 1966. It has the 12 bolt pattern and has never been modified.

Anyway, I've spent the last 3 years working on restoring this truck and originally I thought I would be able to find a nice set of 6 lug rims to fit this truck, but due to the fact I am trying to put as wide a wheel as possible in the rear, I have found out that the selection with the correct offset is VERY limited. (I am leaning towards the Torq Thrust II wheels). It's no wonder so many of you have moved to the 5 lug setups.

So...I sit here this morning contemplating swapping out the rear axels and putting in a set of Moser axels with 5 lugs. My front setup is McGaughy's drop spindles with 6 lugs and I can swap into a 5 lug for about another $150 bucks and swapping out the rotors. No problems there...

My question is threefold:

1. How do I go about selecting the right Moser axels?
2. Because this unit is a posi, is the job of switching these out beyond the reach of a true shade-tree mechanic?
3. What have some of you guys done who have actually made this specific type of switch?

I am not interested in swapping out the entire differential, just the axels. This truck is about a 400 hp street machine...nothing for the drag-strip required.

Thank you,
Tom

[jhrusk]

I think you have a couple options. One being to see if you can find a competent local machine shop and have your axles,drums and rotors re-drilled for a 5 x 5 lug pattern. Secondly you could remove your axles and call Moser with some basic specs and they can get u what u need. They are easy to deal with. With that being said for new 5 lug axles and front rotors you will be in it at least $450. I would try re drilling. Hope this helps

[verdell]

I found a spare set of axles from a '65 and had them re-drilled and switching to five lug drilled and slotted front rotors.

[jonzcustomshop]

speedway sells a kit check this out:
http://www.speedwaymotors.com/1965-1...Kit,46263.html

you should be able to pull the cover, there is a bolt that holds the pin in in between the spider gears, then pull the "C" clips and the axles.

[par4tom]

This helps...I don't know that I am going to redrill the existing axels as there already is a slight whine out of the rear differential.

I found a shop here in Fresno CA that will install new axels, spider gears, seal and lubricant for about $800...does that seem reasonable?

Tom

[par4tom]

This helps...I don't know that I am going to redrill the existing axels as there already is a slight whine out of the rear differential.

I found a shop here in Fresno CA that will install new axels, spider gears, seal and lubricant for about $800...does that seem reasonable?

I figure the cost alone to have custom 6-lug wheels made is going to run me at least twice that in terms of costs compared to the more available 5 lugs...

Tom

[61ChevyPanel]

Hoopers didn't want to sell me new axles without me bringing in my old ones to be measured. It should be easy to remove yours. Remove the wheels. There's a small bolt holding a block in the center. Once you remove the block, push the axles inward, remove the C clips holding the axles in and pull the axles out. It should take five minutes once you get the cover off.

[par4tom]

You make this sound like something I could possibly do myself...I'm pretty handy with a wrench and can figure stuff out, just never rebuilt a differential...

[MikeN]

Replacing axles is EASY. I'm sure you could do it yourself for $350 using the Speedway Motors kit.

[61ChevyPanel]

It's easier than changing spark plugs. You're not going to mess with anything complicated. All you need is 9/16 & 1/2 wrenches.

[Chevy Fleetside]

I saw a 71 5 lug rear diff on craigslist for $300. They bolt right in. I wonder if it is still has it. Here is the link http://sfbay.craigslist.org/eby/pts/5058608110.html

[par4tom]

Fleetside..I checked out the ad and that gearing is not going to work. I've got a .73 overdrive in 4th and last weekend I had it out on the freeway for the very first time, I was at 65 mph at 2000 rpm...

I'm going to give this a try...if I get stuck I'll message back on here. If I change out the spider gears, is that a big deal?

[Chevy Fleetside]

Originally Posted by par4tom

Fleetside..I checked out the ad and that gearing is not going to work. I've got a .73 overdrive in 4th and last weekend I had it out on the freeway for the very first time, I was at 65 mph at 2000 rpm...

I'm going to give this a try...if I get stuck I'll message back on here. If I change out the spider gears, is that a big deal?

I have 3.08 in my truck and I rev 2000 rpm at 70. I also have 26 in tires. I want to get it at 1800 at 70. I just got new tires that are 28" tall and will see what that dose.
The difference between the 71 and 67 diff is about 1 1/2" in width.

[61K10]

there is another company Dutchman axles and they have c-clip axles for $250. they have been in for years. bought a set of axles for my 56 Nomad about 15yrs ago.

[par4tom]

Fleet...just looked at your build thread. Thanks for putting all of that up there. I admire you tenacity in finishing your truck. Looks really nice!!!

61k10 - Let me check out your profile next. I'll look into those Dutchmen.

Question - Do I change out the spider gears while I'm rebuilding this thing?

[jonzcustomshop]

I think the spider gears stay, unless they look beat up, no reason to change them out.

when you have the cover off it will be a good time to clean it up and check everything out for damage. my 65 rear did not have a magnet in the bottom (Keeps parts of chipped teeth out of the gear set) , so I am going to either get one out of a newer rear, or see if I can just get one at the parts store.--my 65 rear needed the magnet, when I opened it up and cleaned it out, there were some pieces in there that would have been better sticking to the magnet than floating in the fluid!!

[par4tom]

Thanks Jonz! That magnet idea is a good one! I'm going to check the spiders out and clean everything up like you said!

Can anyone tell me prior to opening this thing up whether this HC 8 06W rear end is going to have the corse or the 31 spline? I'm not sure I know if there were even differences in 1966 or 1967. It is a posi-traction.

[Captainfab]

The '63 and '64 12 bolts were the only 2 years that had the 17 spline axles. The '65 and up have 30 spline.

[BR3W CITY]

I've had an easy time finding early 70's 12bolts to put in these things. Mines a 3:73 posi out of a 71-72 (donor for the front end stuff as well)

[par4tom]

Front McGaughys replacement rotors - $125 direct. Any opinions on Yukon axels vs Moser?

[par4tom]

Thanks for the input guys...
Tom

[Chevy Fleetside]

You should be able to use up to 87 year model. Only thing is to make sure you get the backing plates also. I have 75 year model brakes and drums on my 72 rear end. I used those brakes because they were 2 1/2" instead of 2".

[par4tom]

Will the existing backing plates not work?

[Chevy Fleetside]

On the 2" brakes the backing plate will be shallow. The 2 1/2 brakes will be deeper. If that makes any sense. I am sure there are late model 2" brake drums. Check out Rockauto.com .

[Captainfab]

Just to clarify. You can not use the '71-'87 5 lug axles in a '63-'70 12 bolt housing. They are 3/4" too long.

If you want to upgrade to the 2-1/2" wide rear brakes, you must change the backing plates also. That is where the extra 1/2" is.