While replacing my fuel filter (man, those things hold a lot of gasoline!), I discovered a rather alarming situation related to the driver's side differential / axle housing.
I'm thinking it's simply the rear brake compensator that's leaking, but thought I'd confer with the world's best consultants for all things Fiat Spider before taking any rash remedial action.
Any and all advice would be warmly welcomed and greatly appreciated.
_______________________________________________ Michael
1981 Fiat Spider 2000 FI
That green color has "leaking auxiliary transmission cooling radiator" written all over it!!!
It is located in the never never land between the back seat and trunk!!
Ok, seriously? What's the green from? The only thing I can think is pinion seal leaking and blowing back on the axle but that does not explain why it is green. Irish roads? Ha
Compensator and boot are not very expensive. Hardest part is loosening the flare fittings. Either buy the very best flare wrenches you can find. Or, use what you have and try to keep them from spreading (which will round out the nut) by holding them closed with Vise-grip pliers.
Good opportunity to flush out the system. Will need to bleed the rear brakes. There is some adjustment available in the compensator setting by its mounting position in its housing. I marked the existing position and re-assembled it.
hard to diagnose a leak with that much build up. I put my money on the rear end and not the brake compensator. normally brake fluid will make everything clean and eat the paint off of anything it contacts. Clean it all off and see where fluid starts to appear.
Could the green be algae from a trunk leak or battery drainage? Cleaning it up will probably help along with the use of dye in the rear axle lube to help trace the source. Is the rear axle lube getting low? Also if the rear brakes are dragging it could be axle lube venting from the heat transferring to the axle.
Brake fluid is about right, but it could be a tad lower than it was last time I filled it. The car has been garaged for the Canadian winter, so not sure where the brake fluid level was 6 months ago.
When I bought the car about 3 or 4 years ago, it had to have the axle seals redone in order to pass inspection. The mechanics who did it used a dye, hence my thought it might be the diff fluid. But I would have thought that the dye would be flushed out when new oil was installed... IF new oil was installed.
The green only shows up when the camera flash hits it, which would also suggest dye.
I plan to clean it all up this weekend and see what I can find out. I'd be surprised if it is coolant because there are no other signs of it anywhere else on the underside. But will definitely check the bottom house. The coolant level remains unchanged, though.
Will also check the diff oil level.
Will let you know what I find!
_______________________________________________ Michael
1981 Fiat Spider 2000 FI
No visible cracks or damage on the diff and axle housing.
The brake line junction that sits right above that spot also seems to be sound and not leaking.
The only thing it can be then is blowback from a leak up front. Possibly the gearbox or the engine oil pan or the rear seals on the engine. Or all of the above. It is a Fiat, after all.
I'm going to try tightening the gearbox oil pan bolts. I installed a new gasket 12 months ago and it has never really sealed properly even with sealant.
That'll be next weekend's job.
_______________________________________________ Michael
1981 Fiat Spider 2000 FI
I suspect it is the dye you're seeing, weeping from the diff. Either the pinion shaft seal or the diff cover. It's not practical to "flush" the diff following axle seal replacement if the axle remains on the car.
Amateurs often over-tighten the gearbox oil pan, as they sometimes do the engine oil pan. Torque spec for the gearbox pan nuts is only 7 ft. lbs.. If you don't have a torque wrench, that's only "snug" with a 1/4" ratchet. Over-tightening warps the pan, causing continual leaks, regardless of attempts at re-torquing. But that's another story; your Soylent Green is coming from the diff.
baltobernie wrote:I suspect it is the dye you're seeing, weeping from the diff. Either the pinion shaft seal or the diff cover. It's not practical to "flush" the diff following axle seal replacement if the axle remains on the car.
Amateurs often over-tighten the gearbox oil pan, as they sometimes do the engine oil pan. Torque spec for the gearbox pan nuts is only 7 ft. lbs.. If you don't have a torque wrench, that's only "snug" with a 1/4" ratchet. Over-tightening warps the pan, causing continual leaks, regardless of attempts at re-torquing. But that's another story; your Soylent Green is coming from the diff.
Hi Baltobernie,
I just slipped under the car for a couple more photos. I can see that you might be onto something with the pinion seal.
Looking at the flow pattern of the oil, it seems to start at the shaft and work its way back to the axle and the bottom rear of the diff.
I have all the parts for a driveshaft rejuvenation (just not the pinion seal), but have been putting off doing it. Looks like I'll have to do it sooner than later.
I'm thinking I'll have to get a set of ramps to get enough height to do it safely. What I'd give to have the space for a hoist!
_______________________________________________ Michael
1981 Fiat Spider 2000 FI
Yep. Looks like it was the pinion seal. Replaced it and took it for a quick spin. No oil leaks there... at the moment.... knock on wood. Not that I'm superstitious or anything.
At the same time I did the pinion seal, I also kitted the driveshaft - new guibo, u-joints, and pillow block. Managed to dent the driveshaft while trying to remove a u-joint. The shaft had slipped in the vise and was resting on the base. Had it re-tubed, only to find the driveline shop wasn't able to balance it because of the Fiat 'special' set up at the transmission end.
So, words of caution for anyone doing their drive shaft kit:
1. As others have suggested in this forum, have a driveline shop do it. For about $200, it's cheaper than going through the headache / expense of trying to find a new shaft, or getting the old one fixed because you managed to inadvertently bugger up something, as I did. And given the Canadian dollar is falling like a stone against the Greenback, best to be smart.
2. Tell the driveline guys that there is no u-joint at the transmission end of the drive shaft. This will cause them to go 'um...?' or say 'no problem'. Either way, you won't be wasting anyone's time, especially your own, and you might get lucky enough to find the last person on Earth with the know-how and equipment to balance a really old shaft.
3. I found it easier to attach the new guibo to the drive shaft before re-installing. That way you only have to worry about the three bolts holding the guibo to the transmission yoke. Propping a ring spanner / wrench against the transmission bracket made it very easy to torque the bolts (51 ft.lbs). It also makes it easier to remove the bolts, too.
4. Loosely attach the pillow block bracket, then use a low-profile jack under said bracket to lift the shaft into place. Loosely attach the pillow block bracket to the underside of the car. Bolt the guibo to the transmission yoke, then take care of the diff flange, then tighten up the pillow block bracket. Makes things much easier to get back into place and naturally aligned.
5. Handbrake cable can be detached and re-attached at the connector bolt to help with drive shaft removal and re-install. I used the handbrake to stop the diff from spinning.
6. I was unable to find an engineer's drawings of the pillow block bracket that I found on my car. The drawings show it as a straight, even bracket. The one I have has a sort of rhomboidal shape, with the pillow block holes located closer to one side. Thankfully, I had some photos of the driveshaft prior to removal, so I was able to reinstall correctly. For the record, the pillow block is bolted with the holes closer to the rear of the car, and the bulk of the 'spare' metal facing the front.
I hope these tips help you out.
_______________________________________________ Michael
1981 Fiat Spider 2000 FI
