Rear bump stop

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Rear bump stop

Post by Bill_qaz »

I noticed whilst checking the car over that the rear offside bump stop was missing. The plate was still secured under the U bolts but the rubber was completely missing. Is it common for the bonding to fail between the metal and rubber. Of course it could be original, so 63 years old. A replacement from ESM is now fitted, although the new U bolts supplied were too long ( possibly I ordered incorrectly) luckily the originals were reusable, they are fitted with double nuts, is this standard?
20250407_142003.jpg
20250407_142003.jpg (1.08 MiB) Viewed 5423 times
Regards Bill
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

Hello Bill,

Not sure about the bonding of the rubber on this part specifically but like all rubber they deteriorate over the years. The engine mounts definitely do come away from the metal. I have done this job and used double nuts on the U-bolts. I'd have to look back at my photos but I'm pretty sure there were double nuts there already and horribly difficult they were to shift. Nylocs might be better for future ease of maintenance. I note your drop link rubber doesn't look in great shape.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

The double nuts undone easily and are refitted with copper slip to prevent any future issues. I noticed the link rubbers, they look worse in pictures than in reality. but they will be replaced this winter when not being used and shockers refilled.
Regards Bill
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

I'm just having a coffee break. Yes there were 2 nuts. Only photo I can find but you can see where the 2nd nuts were. U-bolts weren't too long.

Stephen

IMG_9170.jpeg
IMG_9170.jpeg (1.98 MiB) Viewed 5408 times
IMG_9179.jpeg
IMG_9179.jpeg (2.83 MiB) Viewed 5408 times
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
jaekl
Minor Addict
Posts: 649
Joined: Thu Jun 19, 2008 7:40 pm
Location: Pennsylvania, USA
MMOC Member: No

Re: Rear bump stop

Post by jaekl »

Double nut, one standard thickness and one thinner nut. Because there is rubber in the sandwich, a lock washer would not have been reliable as the rubber took a set as well as limiting the clamping force.
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

jaekl wrote: Thu Apr 10, 2025 11:57 am Double nut, one standard thickness and one thinner nut. Because there is rubber in the sandwich, a lock washer would not have been reliable as the rubber took a set as well as limiting the clamping force.
Perfect explanation! Thank you.
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

"Yes there were 2 nuts. Only photo I can find but you can see where the 2nd nuts were. U-bolts weren't too long. "

Answer to the U bolt length, I incorrectly :oops: ordered for 7 leaf spring instead of 5 leaf :roll:
Regards Bill
philthehill
Minor Maniac
Posts: 11574
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Rear bump stop

Post by philthehill »

Make sure that you have the right nuts!!
Later after market 'U' Bolts had UNF threads.
Self locking (nylock) nuts are an acceptable substitute for the thick/thin plain BSF nuts.
As regards the damper link - I would clean off the crud from around the top nut and soak in penetrating oil ready for the replacing the links. Somewhere in amongst all that crud is a thin split pin and castellated nut..

User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

philthehill wrote: Thu Apr 10, 2025 5:47 pm Make sure that you have the right nuts!!
Later after market 'U' Bolts had UNF threads.
Self locking (nylock) nuts are an acceptable substitute for the thick/thin plain BSF nuts.
As regards the damper link - I would clean off the crud from around the top nut and soak in penetrating oil ready for the replacing the links. Somewhere in amongst all that crud is a thin split pin and castellated nut..
Thanks Phil, the wrong new U bolts came with nyloc nuts but I've refitted the original U bolts with the original double nuts.
I'm aware the upper link mount is castellated nut and split pin, I will be cleaning it off and soaking prior to installing the new links and damper oil change while off but plan to replace the castellated nut with a nyloc. I'm sure the welding torch will aid the removal of the castellated nut if required :tu1:
Some of the crud is actually a thick coating of underseal with dirt stuck to it, so hopefully should clean off reasonably easy :D
Regards Bill
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

philthehill wrote: Thu Apr 10, 2025 5:47 pm Make sure that you have the right nuts!!
Later after market 'U' Bolts had UNF threads.
Self locking (nylock) nuts are an acceptable substitute for the thick/thin plain BSF nuts.
As regards the damper link - I would clean off the crud from around the top nut and soak in penetrating oil ready for the replacing the links. Somewhere in amongst all that crud is a thin split pin and castellated nut..
Yes and although the split pin may come out quite easily, it is certainly not easy to put back. I fitted Nylock nuts instead. Not because I am lazy but because I just couldn't do the split pins.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
SEROWMANMICHAEL
Minor Friendly
Posts: 25
Joined: Thu Jun 20, 2019 9:20 pm
MMOC Member: No

Re: Rear bump stop

Post by SEROWMANMICHAEL »

hope you use axle stands when working under!!
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

SEROWMANMICHAEL wrote: Thu Apr 10, 2025 8:59 pm hope you use axle stands when working under!!
That's Stephens picture looks like a ramp in case the jack comes down. Mine was on a 4 post lift so not a problem.
Regards Bill
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

SEROWMANMICHAEL wrote: Thu Apr 10, 2025 8:59 pm hope you use axle stands when working under!!
My photo is from replacing the leaf springs. What you can't see is that the body of the car is on axle stands. There are also ramps under the car should it fall and the axle was also on axle stands but they had been removed because I had finished and took a photo at the end.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

New links fitted today, no problem with split pins as PO had used spring washer and no pin :roll: Refitted with new nyloc nut and flat washer.
ESM links came with one piece bush, quite tight to push onto pin, plenty of red rubber grease helped,whereas the old ones had two piece. The shockers had good resistance in both directions and fairly equal both sides, so didn't bother with oil.
Attachments
20250415_132811.jpg
20250415_132811.jpg (1.58 MiB) Viewed 5054 times
20250415_141024.jpg
20250415_141024.jpg (287.45 KiB) Viewed 5054 times
20250415_132832.jpg
20250415_132832.jpg (978.92 KiB) Viewed 5054 times
Regards Bill
User avatar
svenedin
Minor Legend
Posts: 3106
Joined: Fri Aug 29, 2014 9:27 am
Location: Surrey
MMOC Member: Yes

Re: Rear bump stop

Post by svenedin »

Good job. I think you actually had more grot to deal with than I did. I did take the dampers off as they were both leaking and not doing their job any more. It's a shame that just checking the oil level is so tedious.

Stephen
1969 1098cc Convertible “Xavier” which I have owned since 1989.

Stephen
User avatar
Bill_qaz
Minor Legend
Posts: 1147
Joined: Fri Jan 14, 2022 7:31 pm
Location: Oxfordshire
MMOC Member: Yes

Re: Rear bump stop

Post by Bill_qaz »

Stephen, It's is mostly a thick layer of underseal with mud stuck to the suface, so on a picture it looks worse than it is in reality. A bit of spray and wire brushing and the nuts came off relatively easily. Of course it's easier on a 4 post lift than lying under the car.
I don't do the clean and painted look, i know its solid with no corrosion and I keep it mechanically sound. Its never been restored just maintained and used, two previous lady owners had it twenty years and it was maintained by the same garage. It came with a huge file of history back to the 70s.
Regards Bill
Post Reply