Rear axle (not rear end) swap - 6 lug to 5 lug
 

I am contemplating switching axles in the rear end of my '63 so I can go to 5 lug rims instead of 6 lug.
At least a dozen years ago I swapped out my original '63 rear end (broken pinion gear) for a complete bolt in rear end from a '67 - '72 that had 6 lug axles. Now I want to put 5 lug axles in that housing.

I found this older thread http://www.67-72chevytrucks.com/vboa...ar+axle+change but it doesn't completely answer my question.

Are there any stock axles that will swap out directly to give me the 5 lug I want?
Greg

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

I believe CPP has 5 on 5" axle shafts for a direct swap.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

71-72 5-lug rears are a different length vs. the 6-lug housings. If you have a 6-lug 67-70 housing, the aftermarket 5-lug swap option is the most efficient way to get it done.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

1970 was a transition year for both the 6 lug to 5 lug as well as the overall differential width. Before ordering axles, you might want to measure yours to be certain of what you have. The '63-early '70 were 62" WMS to WMS. The late '70-'87 were 63 1/2" WMS to WMS. If you happen to have the wider 63 1/2 differential, you could use stock replacement axles. If you have the shorter version, you will have to get the aftermarket conversion axles available from CPP, ECE or Summit.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

I know you said your replacement rear was a bolt-in. Please look at where the panhard bar attaches to the axle housng. Does it attach to a bracket welded onto the axle tube, or does it attach to a lug that is part of the center casting? The first is stock for 63-64 and the second is the 65-up design.

The reason this is important is that the shaft splines also changed in 65, from 17 to 30 splines. AFAIK, the aftermarket shafts are not available with 17 splines. You can use the 30 spline shafts, but those require that you replace the differential side gears. This is not at all difficult to do, but just be aware that you must order the gears if you have the 17 spline shafts in there now.

Ray

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

The original '63 rear end had a bracket welded to it for the panhard bar. The one that I put in many years ago has the panhard attatched to the center section.
Greg.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Greg,
you are getting excellent advice here, these guys know their stuff.
I just did this to my '63 and installed a 30 spline posi unit and new aftermarket 5 lug axles.
There is a down dirty and cheap approach, and that would be to redrill your current axles in a five lug pattern?? although I have never done this.
Also, if your 63 axle has pressed on backing plates, you're probably going to want to stay with rear drum brakes, as there are no easy aftermarket approached to hang discs that I found. You would have to remove the backing plate and weld on a flange. I defer to captainfab on this. I stayed with drums on rear for this reason, all you have to do is get drums for a 71 to have the 5 lug pattern that fit on the 63 brakes. It is a much more robust drum with cooling fins too.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Just did this swap in my 65 Panel.

Its easy.... but there are a couple of tricks... watch the video in this thread MANY times before you start.

http://67-72chevytrucks.com/vboard/s...d.php?t=399080

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Thanks for the advice guys.
I have had the rear end apart a few times, so I am no stranger to danger. I planned on staying with rear drum brakes. I have a complete 5 lug front disc set up, but before I put that in I want to have the rear dealt with.

I am pretty sure that I have 30 spline, 6 lug axles. I would like to know if there is a stock rear end out there that would be able to donate it's 5 lug axles into my current housing.

Would it help if I measured the width of the housing from flange to flange?
Greg

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

As mentioned, the 'transition' year was 70. Some housings were the shorter 63-69 housing; others were wider like 71-87 housings. If you have one of the wider 70 housings w/6-lug axles, you can swap the later 5-lug axles. From what I understand, these a few & far between w/the majority being the narrower housings when 6-lug. The wider housings measure approx 9" from the back-side of the backing plate flange to the center-line of the truck-arm perch on the housing (as measured from the center of the axle tube @ the 12:00 position).

Otherwise (and the better choice) there's aftermarket. New, stronger axles w/zero bearing or torsional wear.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

To my knowledge, there were no stock 5 lug on 5" circle that are the right length for that era truck rear end; when they went to 5 lug, they also went to a different length, although I just read Scoti's, and there may be a few very rare ones out there.
But why run an antique axle? New aftermarket is the best choice, except for redrilling your old axles in a 5 lug pattern.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Reading this makes me realize how lucky I got when I did mine. I just got some axels from a 70-72 truck and slid out the old ones and put the others in...fit like a champ. My 69 has been around the block before I got it, I am guessing my rear end must be the 70 version mentioned above. great info on here, I won't be so quik to tell someone how easy the swap was now.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Thanks guys - I appreciate all this information.
I will measure the distance from the backside of the backing plate flange to the centerline of the trailing arm perch.

If that measurement is not in my favour, who sells aftermarket axles? I need someone who can ship reasonably to Canada (or has a distributor in Canada). I bought my adjustable track bar from CPP and they only used UPS to Canada. That cost me $17 shipping + $53 in duty - not cool.
Greg,

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Greg63, measuring is advised. Recently there was a post on this subject where someone put the later axles in (like hoppa, above) and they fit, sort of. by that I mean that, on closer inspection, the axles were sticking further out, a fact that was hidden by the wider brake drums. the bearings were obviously riding on a different place on the axle but were still working. pictures were posted of the brake drum/backing plate of the mismatch and of the correct axle/housing, but I can't find the post, sorry.

I don't mean to imply the hoppa's axles aren't the correct length, just that there's this other possibility.

found it:
http://67-72chevytrucks.com/vboard/s...d.php?t=390680

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

I just measured the rear end.
It is 56 1/2" from backing plate to backing plate, 7 1/2" from flange to perch at 9 o'clock position, 9" at the 3 o'clock position and 8 1/4" at the 12 o'clock position.
Shorter housing or wider?
Greg

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

8.25" @ the 12 o'clock position indicates .750" shorter than my dimension which would mean the housing is 1.50" shorter overall = 65-69/early 70 30 spline 12-bolt axles.

I took the measurements off of a 71-72 12-bolt, longer 5-lug housing.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

OK, I have a queston that may apply to this thread. I have a 67 with 6 lug and want to go to 5 lug. I got a rear end with the gear i am wanting. It is from a 78. Both are 12 bolt. I am wanting to save the trouble of welding on new axle saddels and having to get a relocation kit for the stabilization bar. Can i shorten my axels on the lathe and swap my entire rear end over?
This would make things easier and cheaper for me.
Any help would be greatly apreciated.

Thank you,
Matt

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

This could work as long as the splines on the axles are long enough. Do you have your own lathe? If you have to pay a machine shop to shorten the axles and cut a new C-clip groove, you would probably be halfway to the cost of the conversion axles. Be sure to check the axle/wheel bearing surface on those '78 axles, to be sure they are going to be worth putting some time/money into.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Thanks for the quick reply Captinfab! No idea on the splines right now and i am still trying to do the math on how much i have to cut off VS were the new end of the shaft will be. I think it will actually not be possiable becuase the ond c clip section will line up in place and not allow the new c clip grove to be strong enough. I will add more info when i get both rear ends apart so taht everyone can learn from my mistakes lol. I hope this makes since.

Thank again!
Matt

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Yeah, I didn't think about the C-clip groove location. The axles will need to be shortened aprox .750". It might be doable.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

if he did go with a 70-87 rear end and welded the brackets to it, how much trouble do you run into with tires rubbing the inside of the bed and backspacing and all that mess.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Seems like I remember reading that 12bolt axles don't have enough material on them to be shortened. I would investigate further.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Why not just drill out for the 5 bolt pattern, I did that on 2 trucks, only cost $120.00 here is what it looks like after it is done.

http://kieth.smugmug.com/Trucks/66-G...Rfcq&lb=1&s=X3

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Here is where my 5 lugs came from. They even tell you the length so what I did was pulled my original axles out first and measured them to be sure. I also have seen 5 lub axles on eBay from time to time for around $40.

Sounds like he has a new rearend so should not be too difficult.

Re: Rear axle (not rear end) swap - 6 lug to 5 lug
 

Main reason for not doing this is cost vs return. In the end, you spent $120 on OE axles with 30+ years of bearing wear. The new axles typically are stronger while also having the correct pattern & zero wear.

I've done the swap both ways. Now that conversion axles are more readily available, I just do aftermarket.