Rear Axle boot leak

[WarMachineM3]

Has anyone gotten this leak repaired suxceasfully without replacing the whole half shaft axle recommended by BMW? Anyone have a DIY?

[chrisjguzman]

You have to replace the whole shaft.

[MineralWhiteF80]

Originally Posted by WarMachineM3

Has anyone gotten this leak repaired suxceasfully without replacing the whole half shaft axle recommended by BMW? Anyone have a DIY?

It all depends on your situation. Do you track your car or drive it very hard for extended times, or do lots of high speed stuff?

It is a common situation in cars that are tracked or driven super hard where the axles get overheated, the air inside the axle boots expands and that air pressure pushes grease out of the boots making it looking like you have a problem. By venting the axle boots, the problem goes away.

If your boot is NOT visibly torn and it just appears that grease has pushed out of the side of the boot, you should be able to either vent the boot (making small pin hole or two) and then leave it alone, or depending on how much grease actually has come out, you can repack the existing boot and install a new strap with the axle in the car for cheap.

If the boot is torn, you will need to remove the axle and things get more difficult.

See this thread for more info, and I am sure there are other threads out there. https://f80.bimmerpost.com/forums/sh....php?t=1620026

My passenger side axle boot leaked grease from the side closest to the diff because I track the car. I noticed it after the very first time it happened when I was inspecting the car after the track weekend. Since I didnt have a ton of grease leak out, I was able to vent the boot and haven't had any issues since.

[WarMachineM3]

Originally Posted by MineralWhiteF80

It all depends on your situation. Do you track your car or drive it very hard for extended times, or do lots of high speed stuff?

It is a common situation in cars that are tracked or driven super hard where the axles get overheated, the air inside the axle boots expands and that air pressure pushes grease out of the boots making it looking like you have a problem. By venting the axle boots, the problem goes away.

If your boot is NOT visibly torn and it just appears that grease has pushed out of the side of the boot, you should be able to either vent the boot (making small pin hole or two) and then leave it alone, or depending on how much grease actually has come out, you can repack the existing boot and install a new strap with the axle in the car for cheap.

If the boot is torn, you will need to remove the axle and things get more difficult.

See this thread for more info, and I am sure there are other threads out there. https://f80.bimmerpost.com/forums/sh....php?t=1620026

My passenger side axle boot leaked grease from the side closest to the diff because I track the car. I noticed it after the very first time it happened when I was inspecting the car after the track weekend. Since I didnt have a ton of grease leak out, I was able to vent the boot and haven't had any issues since.

I thought I read through that thread. Thanks for thr info. Do you know what size clamps and boot I will need? Where can I find this? My local BMW indy said they do not have these parts available anywhere, but I know it's not completely true. Thanks
The boot looked physically intact. It looked like grease just spattered everywhere (above, below, and to the left of the boot, especially closes to the diff. What you explained about pressure wanting to escape is what I think I'm seeing.

[MineralWhiteF80]

Originally Posted by WarMachineM3

I thought I read through that thread. Thanks for thr info. Do you know what size clamps and boot I will need? Where can I find this? My local BMW indy said they do not have these parts available anywhere, but I know it's not completely true. Thanks
The boot looked physically intact. It looked like grease just spattered everywhere (above, below, and to the left of the boot, especially closes to the diff. What you explained about pressure wanting to escape is what I think I'm seeing.

There are a couple things I see here. The big item is that it looks like your axle seals are leaking quite a bit. I can see some axle CV grease spatter, but not all of oil/grime build up below your axle is from the boot. Looks like most of your oil grime is from a leaking axle seal.

I think the correct direction for you is to remove the axles and replace the axle seals in the differential. Then you can really inspect the axle boots closely and verify the boots are intact and only needs a reseal. You can also replace your diff bushings at the same time (if you havent already).

The axle cv joint boots aren't anything special and work exactly like all other cars that have CV joint axles. Source a new axle boot band strap in the proper size shouldn't be hard. A BMW indy shop isn't the best place to look. You need to be talking to a driveshaft/axle shop.

[WarMachineM3]

[QUOTE=MineralWhiteF80;29778944]There are a couple things I see here. The big item is that it looks like your axle seals are leaking quite a bit. I can see some axle CV grease spatter, but not all of oil/grime build up below your axle is from the boot. Looks like most of your oil grime is from a leaking axle seal.

I think the correct direction for you is to remove the axles and replace the axle seals in the differential. Then you can really inspect the axle boots closely and verify the boots are intact and only needs a reseal. You can also replace your diff bushings at the same time (if you havent already).

The axle cv joint boots aren't anything special and work exactly like all other cars that have CV joint axles. Source a new axle boot band strap in the proper size shouldn't be hard. A BMW indy shop isn't the best place to look. You need to be talking to a driveshaft/axle shop.

Any idea what the size of that strap is? And where can I find the axle boots? I assume the axle boots most shops carry. Just asking so I don't have to check myself under the car.

[flo93100]

Originally Posted by MineralWhiteF80

It all depends on your situation. Do you track your car or drive it very hard for extended times, or do lots of high speed stuff?

It is a common situation in cars that are tracked or driven super hard where the axles get overheated, the air inside the axle boots expands and that air pressure pushes grease out of the boots making it looking like you have a problem. By venting the axle boots, the problem goes away.

If your boot is NOT visibly torn and it just appears that grease has pushed out of the side of the boot, you should be able to either vent the boot (making small pin hole or two) and then leave it alone, or depending on how much grease actually has come out, you can repack the existing boot and install a new strap with the axle in the car for cheap.

If the boot is torn, you will need to remove the axle and things get more difficult.

See this thread for more info, and I am sure there are other threads out there. https://f80.bimmerpost.com/forums/sh....php?t=1620026

My passenger side axle boot leaked grease from the side closest to the diff because I track the car. I noticed it after the very first time it happened when I was inspecting the car after the track weekend. Since I didnt have a ton of grease leak out, I was able to vent the boot and haven't had any issues since.

You just clean and that’s good?

[Hotflare]

[QUOTE=WarMachineM3;30009745]

Originally Posted by MineralWhiteF80

There are a couple things I see here. The big item is that it looks like your axle seals are leaking quite a bit. I can see some axle CV grease spatter, but not all of oil/grime build up below your axle is from the boot. Looks like most of your oil grime is from a leaking axle seal.

I think the correct direction for you is to remove the axles and replace the axle seals in the differential. Then you can really inspect the axle boots closely and verify the boots are intact and only needs a reseal. You can also replace your diff bushings at the same time (if you havent already).

The axle cv joint boots aren't anything special and work exactly like all other cars that have CV joint axles. Source a new axle boot band strap in the proper size shouldn't be hard. A BMW indy shop isn't the best place to look. You need to be talking to a driveshaft/axle shop.

Any idea what the size of that strap is? And where can I find the axle boots? I assume the axle boots most shops carry. Just asking so I don't have to check myself under the car.

What did you end up doing ? My rear passenger side is starting to leak to. Making a clicking sound as well