Technical 8.8 Rear End for a Hotrod Info

Whilst not a 'traditionally' used rear end I have been doing some research for using a 8.8 diff assembly in a traditional styled build due to its relatively cheap availability, strength, ratios etc etc.

I pulled it all together here as I thought others might find this info helpful too. The info below is based on what I have learnt and I have not done this yet so use at your own discretion.

As it will go in a Model A highboy with SBC running 4 wheel drums, ladder bar and traverse spring in front rear end I want the following. You may want something different based on application.

Approx WMS 56".
LSD
3.73 or 3.55 ratio
31 Spline Axles
Drum brakes

Which donor?
Based on the above and the power of google my conclusion is that I need to start with a Ford Explorer as it has:
31 spline axles.
Drum brakes up to 90-94.
Is close to the desired width (needs to be narrowed but can use a standard axle - see below)
Can come with correct ratio and LSD.

From what I can see prices are between $200-$400 with you pulling the assembly at the yard.

Identifying the right assembly
When out looking for an rear end assembly in the junk yard if you look up the axle code on the door label you need D4 or L73 for the 3.73 or D5 for the 3.55 LSDs (D2 is 4.11 but a bit steep for what I would want). In this pic the info is F7.



The rear axles should also have 2 tags on the cover bolts. I have read that due to the tags cutting installers at the factory they were phased out but thats not confirmed and they may have not be reinstalled if the cover was previously removed. One tells what size rear (8 8 or 9 75) and the ratio. If it's a 3.55 rear it will say 3L55 or 3 55, if it has the L it's a limited slip. (Thanks Greasemonkey54)



The links below has a LOT of great info re specs of 8.8s.

https://www.therangerstation.com/tech_library/axle_codes.shtml

https://www.therangerstation.com/tech_library/Ford-8_8-axle.shtml

Before buying it remove the rear cover, check for any damage to the gears and check its LSD.



Note: you will need a short axle (passenger side) from another similar rear end so grab one when you are at the wrecking yard making sure its 31 spline too.

I would try and grab the hand brake cables too in the hope that they can be used.

Narrowing
Now the housing needs to be narrowed 2 7/8" and this will give you a final width of 56.5". It comes out of one side hence the extra short axle from the wrecking yard. It does NOT need to be shortened.

When marking out where to cut you need to consider where the suspension mounting points will be and in my case that would be the ladder bars in particular as you dont want to weld on weld if possible.

I found reading this series of pages quite helpful when understanding what needs to be done and how to narrow the housing. There are also a few vids on youtube. Im not good with a MIG so would be farming all this out. Great time to be honest with yourself too

https://thefabricatorseries.com/bui...d-explorer-88-rear-axle-part-1-prelude-and-qa

If doing it yourself or having a friend do it, whilst kits are available (see old eBay link below) machining up a set of 4 pucks and using a 1 1/8" bar you could have a simple jig to keep everything square as you weld up everything including suspension mounts.

https://www.ebay.com/itm/Rearend-Narrowing-Fixture-Bushings-8-8-Ford-Rear-End-2-535-2-25-3-062/233666591243?_trkparms=aid=1110001&algo=SPLICE.SIM&ao=1&asc=225086&meid=d386069f0fd8476cba2214127279a0dd&pid=100623&rk=4&rkt=5&sd=324243324757&itm=233666591243&pmt=0&noa=1&pg=2047675&_trksid=p2047675.c100623.m-1

It may also a good time to strengthen the assembly by welding the tubes to the diff housing as per the video below (may not be needed?). After all the welding its probably worth getting it straightened if you did it yourself.




Reputable rebuild kits (bearings and seals) run about $100 and that might be a couple hours well spent whilst its out on the bench particularly as you'll have it all apart for using the straightening bar when welding. All you really need is a press. Just make note on which side any spacers go!

https://www.wyoulucky.com/index.php?main_page=product_info&products_id=74690

You can buy heavy duty covers too and some do have drain and fill plugs which would be handy. Many are a bit too bling for me but this painted black might work.



Suspension Mounts
As the explorer axle tubes have an outside diameter of 3.25" may also need custom ladder bar brackets and lower spring mounts (traverse spring) as 3" are the largest I have come across so far. (SEE POST BELOW FOR LADDER BAR BRACKETS) Obviously everything will need to be tacked in place when setting pinion angles then finished welding. The bar and pucks mentioned above would come in handing for that too.

Stud patterns
The wheel studs are 5 x 4.5 for the Explorer. If you are already planning or currently running that all good. If not you could get new axles with the 5 x 5.5 pattern which might be a good idea, especially if you cant find the extra short axle at the wrecking yard. The run about $400 a pair. Please see comments below about being able to drill the rear axles to 5 x 5.5 negating the need for new axles although Im yet to find a reference to anyone actually doing this.

For the front if you have both short axles from the wrecking yard hence running 5 x 4.5 you can use adaptors or redrill your front hubs and drums to the 5x4.5 pattern with there being a lot of love for using these to make sure its done accurately. As I plan to run old 45 Fin Lincoln drums this would have to happen any way.

https://www.hellsgatehotrods.com/shop/drill-guide/

Wheels
For the 16" 5 x 4.5 wheels I want to run the 49-52 Shoebox optional Ford wheels on V8s and apparently stock on the 6's (TBC) would be my preference but there are several other options and here's a link to where some of these are discussed.

https://www.jalopyjournal.com/forum/threads/options-for-small-ford-bolt-pattern-slim-16-rims.225945/

Brakes
I looked for some brake options and found this info re backing plate bolt patterns although it shows the OD for the axle tube that is smaller than the Explorer's. This being the case just confirmed I would use the stock Explorer brakes.



Jimmy six mentions in comments below the need to change out the wheel cylinders to a smaller size if not running power brakes which is how I will setup my car. He went 15/16 but also mentioned 7/8 might have been better. Please see his comments re this and the master cylinder too.

As the explorer comes with 10" drums straight from the car I understand you can use finned Aerostar drums, which whilst not 45 fin Buick they seem to look a little better. I found that info at

https://www.therangerstation.com/tech_library/Brake_Upgrades.shtml



There is also brake rebuild kits available with finned drums but they seem very cheap so Im a bit suss on them but each their own.Whilst its apart though some new wheel cyclinders, shoes etc might be a good idea too. (Please see comments in the replies below about changing the wheel cylinder size if you arent running power brakes).

https://www.carid.com/powerstop/1-c...oe15312dk.html?singleid=1074997543&url=810466

Another option as discussed in a couple of the replies by Jimmy Six below is upgrading to 11" brakes from a F150. For a light little A coupe its probably over kill but may well be handy for someone else.

Driveshaft
For the driveshaft you need a 1310 yoke adaptor which is spicer part #2-2-1379 which is available from NAPA and is about $50 as I understand it. As each car will be different a custom driveshaft will be needed as best I know. Unless you have done it another way cutting down an existing shaft? If so can you let us know details please.



Well I think that captures what I have learnt of that and hope that helps other people as it has me.

Thanks
Pete

 

Not sure about car 8.8s, but the Ranger and Explorer ones have axle flanges that do not have access holes in them, like older axles, and are machined on both sides.

This means that they can be re-drilled for other patterns, such as classic old-school Ford 5-on-5-1/2", using the aforementioned drill guides.

 

Including Mustang 8.8" , They all have C-clips so they have full circle flanges.

Here's the axle widths [flange face to flange face]


S-197 Mustangs and Ford Explorers are 31 spline axles with the larger diameter axle tubes. .
The S-197 mustangs are 65.4" wide

 

Cheers. Did those Mustangs come with drums?

 

The Ranger info there is not correct. I have a 1991 Ranger 8.8 in my early Falcon. It is 56-1/2".

• 1990-1992 Ford Ranger 8.8-Inch Axle – 56.50 inches
• 1993-2009 Ford Ranger 8.8-inch Axle – 58.50 inches.

 

Is that WMS to WMS?

 

Always. Any other measurement is near useless.

 

I have 8.8s in all 3 of my cars and they all have the 3.55 gears.... One has half shafts with a 460 hp cammer in front of it....

 

I have been considering using one of these axles and thought I was stuck with the six lux pattern. To go to a 5 lug I thought it would be a full axle change, but you have got me curious. Mine is out of a 2015 ranger so may be different.I would like to here more.

Thanks

Steve

 

I my Ranger 8.8 is now 4-lug. As long as whatever you are re-patterning to does not have a hole that lands where another one already is, you are good-to-go.

Any machine shop that is still alive in this economy can re-drill a flange, and whatever brake components you have.

The inventor of the drill guides sold by Hell's Gate made a custom one for me, to go from 5 to 4, so I did my own. I believe he's out of that business now.

The pattern on your axle is 6-on-5-1/2" Any 5-stud pattern on a smaller circle is easy.

A 6-stud pattern has studs at 0º, 60º, 120º, 180º, 240º, 300º

A 5-stud pattern has studs at 0º, 72º, 144º, 216º, 288º. On the same bolt circle of 5-1/2", that might get into hole overlap.

 

Yeah, no matter how I rotate the two patterns, there is hole overlap.



That is going from 6-on-5-1/2" to 5-on-5-1/2".

Smaller patterns, like modern Ford passenger car should fit just fine.

 

I just noticed that you are down-under.

The USA took a break from having the Ranger after, 2011, and we did not see it again until 2019.

By then it was the "worldwide" version, and had a Dana M220 rear axle, not an 8.8.

I have no experience with that one. You will need to pull a caliper and rotor, to see what is in there.

 

@gimpyshotrods, how much is the pinon off set and was it an issue with the Ranger 8.8 in your Falcon? Thanks.

 

It is something near 2-1/2".

My tunnel is not stock, or it may have been an issue.

My Falcon has been lowered about 4", has a 3" driveshaft, and a T56 all packed in there.

No part of the original tunnel would accommodate all that.

The tunnel is also additionally higher, and shaped to fit the bottom of a 1960 Thunderbird console, from rear seat, to dashboard.

 

Thanks. Thinking of one for my '54 Ranch Wagon and not sure it the stock tunnel will handle it.

 

I don't question the strength of the 8.8 and finding the right gears is just keep hunting for the one you want most of the time.
I do question the wisdom of the do it yourself at home axle narrowing. It's like watching those "we build gaudy rigs with big billet wheels" boys in Houston narrow and axle housing with a 4-1/2 cut disk and a mig welder on TV, yea it can be done but is it wise to do it?

 

I won't narrow without pucks and an alignment bar.

I bought them for most more common axles long ago, periodically adding in less common ones, on-request. For those, I either break even, or take a small hit, but at-least I expand my capability.

 

The 8.8" Ford is a fantastic rear axle, and in stock form one of the strongest out there. Many others need a fair amount of upgrades to get to equal strength. I've been using them for years, and love them. Yes, they don't look as good as a Ford 9", but they save me tons of bucks, which I can use elsewhere.

The short side axle swap to narrow it 2 7/8" doesn't have to come from a similar limited slip rearend. It can be from an open differential, and I prefer one from an open differential, since they're way easier to remove. My local wrecking yard only charges $20 for an axle shaft, and $200 for a complete axle, so for $230 I can have a posi 8.8" in several ratios. The 3.73 ratios seem to be the most commonly found, with the 4.10 ratio being fairly rare, and the 3.55 being pretty tough to locate also.

I just put an 8.8" in my buddy's '57 Chevy truck, and we went with a 2003 disc brake axle. I put a 1994 drum 8.8" Ford in my '39 Chev coupe last year. It was a spare I got as a backup for my BBC powered Falcon gasser, but never broke the original donor 8.8", so never used this spare. Had a spare short side axle too, but I needed full width on my '39, so the axle will sit here drawing dust until it ruts away now. Bought that one on a half price holiday weekend sale for $100!

One other note. The 8.8" Ford and the 12 bolt GM share some parts interchangeability also, since they're built by the same makers. If you look at clutch packs fr both in a 31 spline, they have the same part number!

 

This one under a 56 Ford Victoria. Narrowed to 56-1/4”, pre-95 11x2-1/4” drums from a F-150. All extra cast metal removed from the case, yoke conversion, 2.74 gears (new not available). Works great. On other threads on the Hamb.

 

I have one out of a 2000 ranger - it is 58.5 wms and the total pinion offset is about 4"

 

Great thread with lots of info and research by the OP.

One thing that might be nice to check is the length of the splines on each axle. They are probably longer than necessary which could allow for a little additional shortening, or shortening less than what the shorter axle does.

As for the hole overlap when going from 6 lug........just weld the holes up and redrill. Leave one lug if it's on the correct bolt circle........

 

Thanks do you recall what year the F150 brakes came off?

 

I believe the 96 had the first rear discs. The drums were used from the first to the last on the 8.8 with drums. I was told mine were 89 backing plates. I checked the numbers on the shoes and I believe they were from 79 on. I do know the 11” fit my e-brake with only an enlargement of the cable hole from metric to inches with all the stock parts. I changed the wheel cylinders to a smaller size because I did not use a power brake vacuum assist which was advised by every brake parts supplier I talked to. The front was changed after the rears were functioning perfect. Wilwood 4 piston fronts with their MC was installed.... no power.

 

Thanks. By chance do you recall what size you went to as I will be running drums up front so no power either. Thanks.

 

Stock were 1” for power brakes. I went to 15/16”. 7/8” probably would have been better but I knew I was going to discs in the front.
Any time you go to smaller wheel cylinders or master cylinder you need to make sure there is enough travel on your pedal. My master is 7/8” and it stops fine, not power but better than all drum.
If you put A 7/8” MC on power brakes you might throw yourself thru the windshield that’s one of the reasons why the manufacturers went to larger diameter ones when power discs are used.
One other thing the stock brakes on my 56 were 11x1-7/8“ wide. The F-150’s are 11x2-1/4”. That’s a lot more rear shoe contact surface. I made many adjustments to the prop valve to get comfortable with it using front discs. I drove it a month or 2 with all drums and could feel a slight difference from the stock narrower ones. Good luck.

 

My '96 F-150 had drums on an 8.8 with 3.55s....

 

Great information filled post OP! Thanks for the research.

Sent from my SM-G930V using The H.A.M.B. mobile app

 

Thanks. It was nice to give back a little as I learn so much from here. I try and update the post as I learn more so if it seems other's comments are duplicating the original post that is why.

 

While the 8.8 is not "traditional " it is definitely traditional hot rodding. Go to the bone yard and pick the best parts you can!

Great information in the post but I will add one thing... Ford 8.8 and 9.75 rear axles have 2 tags on the cover bolts. One tells what size rear (8 8 or 9 75) and the ratio. If it's a 3.55 rear it will say 3L55 or 3 55, if it has the L it's a limited slip

 

Number of teeth on the ring gear divided by the number of teeth on the pinion equals the rear gear ratio..... Just in case anybody was wondering.....
That goes for all rear ends...