Difficulty of re-sealing '78-up rear axle?

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TimpanogosSlim
Posts: 237
Joined: Wed Feb 06, 2013 12:45 pm
Your car is a: 1977 124 Spider

Difficulty of re-sealing '78-up rear axle?

Post by TimpanogosSlim »

I just brought home a complete rear axle from a '79 spider 2000. Looking forward to the 3.9 gearing. Also wondering if those guys in russia would be willing to ship me a lada LSD.

Anyway - while it seems to be entirely sound mechanically, it leaks from every seal. The exterior is also way crusty and i would like to clean it up and paint it.

how hard of a job is that? Time i have. Access to shop tools like hydraulic presses i can finagle. I kinda don't want to spend the $400+ an axle shop would charge me. Near as i can tell the carrier bearing is fine. The cluster was missing from the car i pulled it off of but i don't think there are a whole lot of miles on it.
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Sparky
Posts: 114
Joined: Wed Nov 02, 2016 10:53 am
Your car is a: 1978 Fiat 124
Location: Pacific Northwest

Re: Difficulty of re-sealing '78-up rear axle?

Post by Sparky »

Keep us updated on how your clean-up and re-sealing of the axle goes. It's a ways down my list of things to do.
Regarding the Lada LSD, my understanding is that those only fit the earlier style axles. The later axles have the benefit of the 3.9:1 gearing and compatibility with Allison's big rear brake upgrade, while the earlier axles have lots of cheap LSD options... j
-= 1978 Fiat Spider =-
vandor
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Your car is a: 1971 124 Spider
Location: Texas, USA

Re: Difficulty of re-sealing '78-up rear axle?

Post by vandor »

To relace the front seal you have to remove the flange. According to the manual, any time that nut comes off and lets the pressure off the crush sleeve, the sleeve is supposed to be rpelaced. To properly replce it and set if the ring gear has to come out, which is a lot of work.

A lot of people simply mark where the nut is in relation to the pinion (not the flange!) and upon reassembly they put the nut back in the same position, or a hair tighter. I've done it a few times and it has worked, but you have to know that it is not the 'proper' way, and there is a small chance that things won't be right after assembly, ie. the rear axle will be noisy. Of course if you have never ran this axle then you don't know if it was noisy before or not.

BTW, if you are replacing an early type axle you will need the later panhard rod for the late axle.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
djape1977
Posts: 985
Joined: Sat Apr 21, 2012 6:08 pm
Your car is a: 1970 fiat 124bc
Location: Belgrade, Serbia, eastern Europe

Re: Difficulty of re-sealing '78-up rear axle?

Post by djape1977 »

russian (Lada) lsd will fit only early type rear axle, one in between torque tube and one you got now.
your "new" rear axle is 131 type. no cheap lsd for it i'm afraid.

there is a 3.9 diff for early type rear end and it can be delivered a s a complete new unit, with lsd already fitted and everything set up and torqued, ready to bolt in. i have already sold few to US.
you get new bearings and save on expensive specialist labor setting up diff clearances.

Image

available final drive ratio options are
3.9
4.1
4.3
4.44
4.7
5.2

and regarding LSD
torsen - torque sensitive
colloti - clutch pack type

any combo of the above is possible
carl

Re: Difficulty of re-sealing '78-up rear axle?

Post by carl »

You say this rear leaks from every seal but does that mean it's grungy all over or you have installed it in the car and it shows leaking everywhere? If you have not installed it yet I would just clean it up and maybe change the axle seals behind they brakes as they are rather easy to do. Then you can get a better idea of where it's leaking from once the car is in use.
DRUMMOND
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Re: Difficulty of re-sealing '78-up rear axle?

Post by DRUMMOND »

It is a time consuming job to get all the crust off. took me two weeks total.
Only three seals to replace. the left and right outside seals are easy take 5 mins each. drive shaft seal much longer. But as someone says do the easy stuff first install it see what leaks.
All the seals can be replace on the car.
Some photos of axle rehab
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RRoller123
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Re: Difficulty of re-sealing '78-up rear axle?

Post by RRoller123 »

Nice!
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
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Sparky
Posts: 114
Joined: Wed Nov 02, 2016 10:53 am
Your car is a: 1978 Fiat 124
Location: Pacific Northwest

Re: Difficulty of re-sealing '78-up rear axle?

Post by Sparky »

vandor wrote:To replace the front seal you have to remove the flange. According to the manual, any time that nut comes off and lets the pressure off the crush sleeve, the sleeve is supposed to be replaced. To properly replace it and set if the ring gear has to come out, which is a lot of work.

A lot of people simply mark where the nut is in relation to the pinion (not the flange!) and upon reassembly they put the nut back in the same position, or a hair tighter. I've done it a few times and it has worked, but you have to know that it is not the 'proper' way, and there is a small chance that things won't be right after assembly, ie. the rear axle will be noisy. Of course if you have never ran this axle then you don't know if it was noisy before or not.
A bit off-topic, I've finally gotten around to cleaning up the rear axle and was really disappointed to spin the input shaft and discover I've got 2 later style axles and they're both ~4.3:1. So while I really like that I can spin the caliper brackets around or easily replace them for swapping out the rear calipers, the gearing seems sub-par and there's no reasonable-priced lsd options...

I definitely need to reseal the pinion/input seals 'tho, there's oil just dripping out the end of the end of the flange around the pinion nut. If anyone has instructions on the 'proper' way to reseal it, I'd love to see some pictures & details.
Thanks
-= 1978 Fiat Spider =-
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nelsonj
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Your car is a: 1972 Spider 124

Re: Difficulty of re-sealing '78-up rear axle?

Post by nelsonj »

Looks great! But do you really sleep with it in your bed???
Image
Simi Valley, California
Spider 1800
Romans 10:9
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