Swapping Gears 9in

[bmcgc]

Ive read some tech articles.

I have never opened a Ford 9in.

This weekend Im swapping pumpkins.

From what I can determine its 5 steps.

1. Unbolt axles and pull out a couple inches.
2. Unbolt pumpkin and remove.
3. Install new pumpkin.
4.. Fill.
5. Reinstall axles.

Is that it?

[LM14]

Drain the center section before starting.

Pull your axles out at least 4" to get them completely free of the carrier.

You need either a gasket or silicon between the pumpkin and the housing.

Be sure your axle slides all the way back in without pulling it in with the T-bolts.

Check the condition of the gasket between the end of the housing and axle retainer. Those sometimes get skipped and leak into the brake drum.

It can be pretty hard to break the seal between the housing and the pumpkin if it hasn't been apart for years. Look at the edge of the pumpkin and you will see a few places you an pry with a big screwdriver.

If you are really smart, you'll find somebody else to lift the pumpkin in place! We changed gears twice a week in dirt modifieds and stock cars with 9" rears and they are just awkward to handle.

Have fun!
SPark

[graybeard]

Ditto on the help deal. I too remember changing those & not thinking anything about it. After thinking I'd be better off with 3:00 to 1 instead of 3:25s (for over 25 years). Remembering what you did easily at 23 versus actually doing it at 64 isn't the same thing. Next one I change I'll design a cradle to sit in my floor jack, with tilt ability.Bone spurs in both shoulders that were screaming by the time I got the pumkin back in. The first several steps are cake with ice cream as opposed to the installation part.

[ICEMAN6166]

yes help is needed for that these days

i used to juggle those at 23, along with fe iron intakes.
30 years later tools and extra hands are a necessity.
my days of hercules feats are over.

[William-in-St George]

Be sure the axle spline count matches the replacement (28 verses 31). I take the axles all the way out and inspect the bearings, felt drip seal and the axle seal in the end of the housing. New gaskets and a bit of silicone as needed. If the axle won't come out, bolt on an old rim and hit it with a bfh. Wear gloves and safety glasses. Patience.

[bmcgc]

Im ready to swap the gears in my 66 F100.

The rear end I bought is a 2.75 trac-lok.

So on second thought my axle seals do not currently leak and there is a good chance that they are orginial.

I think there is little chance that I am going to slide the axles out, then back in and end up with no leaks.

Should I roll the dice and hope the seals are ok, or go ahead and replace the bearings and seals?

I have help to put the gears in, but due to my health I am not able to remove and install the bearings and seals. How much should I pay for that service?

Does the rear take 80w90 gear oil? Any advantage on a truck this old to useing syn?

Is there a vent in the diff? I dont see one.

[charliemccraney]

The vent should also hold the brake hose on. I had an axle leak years ago and it was due to a clogged vent. So make sure it is clear.

[bmcgc]

Anyone have the part numbers for the bearings and seals?

Ive been looking on the part house websites and Im not finding any consistant information.

My 66 has the 28 spline tapered 9in, just like millions of other ones just like it.

[Hunter's 64]

My 66 has the 28 spline tapered 9in, just like millions of other ones just like it.

What did the center chunk come out of ? 28 spline or 31

Danny

[ICEMAN6166]

i would replace the seals and bearings just because i had the axles out and would want to put back together with new parts.

not sure what shop charges would be but axles are kind of a pain to chill unless you have a chest freeer.not sure how your wife is with bearings in the oven either.

..

[frank66]

If the axle won't come out, bolt on an old rim and hit it with a bfh.

I always put the brake drum as a slide hammer. Put the drum on backwards, screw 3 lug nuts on for only a few threads and pull the drum towards you for a few quick shots.

Also, make sure the yoke for the U-joint is the same. They come in different lengths and can require different u-joints. Check width and cap diameter.

[bmcgc]

Rain the next couple days so Im on hold.

I may move the spring perches and use the whole rear end. Is 40in the correct width for my 66?

The donor rear is in excellent condition. IMO its easier to swap rears than it is to swap gears.

I get bigger brakes, Im not mis-matching parts, and I keep my 3.25 rear end intact. Never know when that will come in handy.

[charliemccraney]

If you swap the entire rear, you will need to make sure the spring pads and shock mounts are located properly. You may have to do brake line work. Maybe the parking brake cables will need to be changed if the brake drum ends changed throughout the years. If the overall width is different, maybe there will be wheel and tire issues. Does it have the same wheel bolt pattern?

It will potentially be a lot of work to swap a non stock axle. I'd swap the gears. IF you ever need another axle, the other will be there, ready to modify, if need be but if you're really concerned about that, sell off the remains and find one that simply bolts in at the junkyard. The numerically lower ratio ones are easy to find - I was really thinking a 4.10 would turn up in no time but not yet. "Economy" rears on the other hand are everywhere.

[Hunter's 64]

IMO its easier to swap rears than it is to swap gears..

Personaly I would rather change center chunk, than remove and replace a rear end that has to be modified/ weld on new spring perchs and shock mounts , Also I would pull shafts and repace bearing and seals anyway, Even if I was to swap rearends, I would put new bearing and seal in it anyway, why do all that work just to find out the bearing or seals were on their way out .


Danny

[bmcgc]

As I said, I get bigger brakes and Im not mismatching parts. I think the wider rear will fill out the rear wheelwells nicely.

My guesstimate is that I have 40in between spring seats and the 77 rear is 44in.

Ive got a few days to chew on it, I have to make a summit run to buy a cam for the Mustang and they have the proper spring seats for $20 + another $20 to get them welded on. The shock mounts are in the right spot, nothing needed there.