Bronze Spigot Bush

[The Wookie]

I'm currently trying to get hold of a replacement spigot bush (goes between the crank and the input shaft) for my South African Defender with a BMW M52 engine in it, as it seems to be the only part that isn't a parts bin special.

The Land Rover Dealer I've contacted locally has been very helpful (bloody unusual experience considering what they're all like in Surrey) and is getting in touch with Land Rover Technical to try and see if the part is available somewhere but I'm not holding out much hope.

I've got the old part out (using an awesome trick of hydraulicing it out with grease and a 1/2" socket extension, thank you internets) and although it's not knackered it's got quite a few grooves, is slightly ovaled and must have taken a beating from the DMF that went off centre. Pictured here:



I have precision machining facilities available here so I'm thinking about the prospect of having one knocked up (or even a few to keep as spares). So my questions are

1 - The TD5 uses a self lubricating bearing (replacement instructions dictate NO grease) and I'm guessing this is the same as it didn't seem to be greased (although it was full of crud and dust) so presumably Sintered Bronze impregnated with lubricant. would anyone know if there's a particular grade of material that needs to be used?

2 - Anyone know a supplier that I can get sintered bronze cored bar from in small quantities?

3 - I'm going to take the minimum measurements I can pick up with a caliper gauge on the ID of the spigot on the assumption that it'll be as good as a worn one but better than a shagged one. Is there any rule of thumb for minimum clearance? Even better, does anyone have a new TD5 spigot knocking about to measure as that will have the correct I/D using the same gearbox input shaft.

Thanks all!

[100SRV]

Have you tried Automotive Components Remanufacturing (Roland Marlow), he works on myriad powertrain combinations and might be able to help.

Alternatively Jeremy Fearn used a BMW 6 diesel in his Wildcat coupled to a manual gearbox; maybe a part common to the BMW engine of that era? I am thinking P38 diesel manual (if such a thing exists).

100SRV

[DVandrews]

In the past I have made spigot bushes from Colsibro bar which has great natural lubricity.

Dave

[The Wookie]

100SRV said:

Have you tried Automotive Components Remanufacturing (Roland Marlow), he works on myriad powertrain combinations and might be able to help.

Alternatively Jeremy Fearn used a BMW 6 diesel in his Wildcat coupled to a manual gearbox; maybe a part common to the BMW engine of that era? I am thinking P38 diesel manual (if such a thing exists).

100SRV

The P38A Diesel Manual donated its flywheel, bellhousing and clutch assemblies but sadly uses a different input shaft and adaptor to relocate the shifter and the pilot bearing used has a much smaller I/D.

Will give ACR a go if I'm still struggling cheers

[The Wookie]

DVandrews said:

In the past I have made spigot bushes from Colsibro bar which has great natural lubricity.

Dave

Lovely, good info thanks!

[PeterBurgess]

You would be better using the 'proper' material which is Oilite.
http://www.bowman.co.uk/products/oilite

Peter

[Pumaracing]

One thing I've learned over decades of making bronze bushings for such things as valve guides, conrod little end bearings, spigot bushes and other stuff is you can spend a lot of time fretting over the exact grade to use but it makes little difference in the overall scheme of things as long as it's a decent grade of proper bronze (copper/tin based) and not just high tensile brass (copper/zinc based). The yanks love silicon bronzes whereas we tend to favour phosphor bronzes of various mixes. I've used aluminium bronze for valve guides and it's a bugger to machine but near as dammit indestructible.

Whatever you use someone else will have a different idea. Oilite is fine of course but a non self lubricating bronze with the addition of a smear of grease will do quite nicely.

The o/d press fit should be between about 0.5 and 0.75 thou to provide a light retention and because the i/d will compress in a tad during fitting you'll want it machined about 1 thou minimum over the gearbox shaft size to allow for this plus a bit of clearance. Lightly chamfer the outer facing lip to cope with any distortion when you tap the new one in.

[DVandrews]

One problem is how much you may have to buy to make one bush, if you could let me know the OD then I may have some Colsibro bar I can let you have, I buy 5 metres at a go for small end bushes. It isn't cheap at the minimum length / weight you have to buy.

Dave

[PeterBurgess]

I have used this firm before, they stock a lot of off the shelf bearings one of which you may be able to adapt.

http://www.bearingboys.co.uk/Oilite__Bearing_Bushe...

You can machine the bushes if you are careful.

Oilite is best as it is designed for the job. Uisng plain non oil filled brass/bronze bearings is not really sound engineering workshop practice and maybe a get you home on a rally-type repair, grease and dust do not mix well. Some conversions use roller bearings, but I have always thought these would be susceptible to debris mixing with the grease/oil and causing damage.

I dont think you can buy oilite in bar lengths, I think the manufacturing process is sintering each formed bush then oil filling.

Peter

[Pumaracing]

PeterBurgess said:

Some conversions use roller bearings, but I have always thought these would be susceptible to debris mixing with the grease/oil and causing damage.

The needle roller bearings used as standard in many engines such as the Pinto have an oil/dust seal built in. However plain bronze bushes are much more tolerant of dirty operating conditions than roller ones which is why they do work fine in practice whether oilite or not.

[The Wookie]

Great info thanks all! From the sounds of things I would like to go with the oilite if possible.

In terms of machining oilite, having done a bit of research and apparently they can be machined done with extremely sharp tooling that will keep the pores in the material open rather than flattening them over. Any opinions on this?

ETA - This looks promising:

http://www.bearingboys.co.uk/Oilite__Solid_Bars-37...

[PeterBurgess]

We use very light cuts, v small radius tip (if any) and don't clamp more than minimum to hold the workpiece. Comes off as a powder. You should get close with the off the shelf item and if necessary make an external sleeve?

Good luck, I hope you get it sorted.

Didn't realise one could get solid bar.....glad I haven't got an 8" one

Peter

[Pumaracing]

The Wookie said:

Great info thanks all! From the sounds of things I would like to go with the oilite if possible.

In terms of machining oilite, having done a bit of research and apparently they can be machined done with extremely sharp tooling that will keep the pores in the material open rather than flattening them over. Any opinions on this?

ETA - This looks promising:

http://www.bearingboys.co.uk/Oilite__Solid_Bars-37...

Struth. 15 squids for a bit 3/4" diameter x 2" long?

Just out of morbid curiosity what are the dimensions of the bush?

[The Wookie]

Pumaracing said:

Struth. 15 squids for a bit 3/4" diameter x 2" long?

Just out of morbid curiosity what are the dimensions of the bush?

Yep, just had the negative response from Land Rover and had to fork out for a 6" length which was painful!! Still at least it means Ian has got a couple of goes at it and can make me a couple of spares to put in the cupboard if it needs another at some point!!

Bush is 32/30.4mm OD, ~22.3mm ID and 20mm long

ETA - Also had a close look at it with a high powered eyeglass and it does look to be oilite as it has pores in it, although it has clearly been turned/machined on every surface so I'm not too worried about making it as it's clearly a low volume part!

Edited by The Wookie on Wednesday 26th February 14:13

[Pumaracing]

The Wookie said:

Yep, just had the negative response from Land Rover and had to fork out for a 6" length which was painful!! Still at least it means Ian has got a couple of goes at it and can make me a couple of spares to put in the cupboard if it needs another at some point!!

Bush is 32/30.4mm OD, ~22.3mm ID and 20mm long

ETA - Also had a close look at it with a high powered eyeglass and it does look to be oilite as it has pores in it, although it has clearly been turned/machined on every surface so I'm not too worried about making it as it's clearly a low volume part!

That's a big bugger. I'm more used to the Ford 4 pot sizes in the Pinto, Crossflow, CVH etc. 21mm x 15mm i/d.

Anyhoo. I know what I'd have done but then I'm a tight bugger. Buy a new 8566l spigot bush which is a princely 80p from Landy dealers and 27mm o/d and make up a steel sleeve for it from a bit of scrap bar. Tap the sleeve into the crank, tap the new spigot into the sleeve. Job's a good un.

http://landypart.com/8566l---spigot-bush-1961-p.as...

[The Wookie]

Tempting but the hassle of getting the damn thing apart and the expense and rarity of the flywheel would definitely put me off!!

Just found this useful page for anyone thinking of machining their own oilite bearings:

http://www.bowman.co.uk/products/oilite_technical

[Pumaracing]

In engineering terms there's no real difference between making a simple steel sleeve for a standard bush which you can change easily and very cheaply if ever required and making a custom bush for shed loads more money which you can't. However, not my engine I suppose.

[The Wookie]

Hi chaps, appreciate all the helpful advice that was given and thought I'd give a quick follow up for closure

Finally had a free weekend where I was actually at home (and not hobbling around in pain after crashing at Thruxton) and managed to get the whole shebang back together.

In the end I measured up the old one, obtained the specified input shaft diameter and got our R&D machinist here at Alcon to knock me up a new bush in his spare time out of the rod of oilite bronze I bought using some instructions I found online.

Soaked the bush in hot oil for about 20 minutes then left it in a pot to soak overnight, fridged it, located it firmly by hand then tapped it home with a conveniently sized broom handle and a light hammer.

Gearbox went on a treat and everything seems to work perfectly for the first time in about 5 or 6 years!

The oilite bronze was bloody expensive (although I now have enough to last me for the next 50 years at current rate) so in hindsight I probably should have gone for Pumaracing's option of machining an adaptor for the crank and using a TD5 spigot as it would have saved me 70 or 80 quid. Having said that at least I've got peace of mind that it's all as it should be.

I've kept the design on file here and I do have enough Oilite bronze of appropriate size to last me a lifetime so if anyone with a 2.8i Defender is looking for one and stumbles across this thread then drop me a PM! Happy to knock one up for the cost of the length of bronze and some more beer for Ian!

Edited by The Wookie on Thursday 5th June 10:56

[tommobot]

The Wookie said:

Hi chaps, appreciate all the helpful advice that was given and thought I'd give a quick follow up for closure

Finally had a free weekend where I was actually at home (and not hobbling around in pain after crashing at Thruxton) and managed to get the whole shebang back together.

In the end I measured up the old one, obtained the specified input shaft diameter and got our R&D machinist here at Alcon to knock me up a new bush in his spare time out of the rod of oilite bronze I bought using some instructions I found online.

Soaked the bush in hot oil for about 20 minutes then left it in a pot to soak overnight, fridged it, located it firmly by hand then tapped it home with a conveniently sized broom handle and a light hammer.

Gearbox went on a treat and everything seems to work perfectly for the first time in about 5 or 6 years!

The oilite bronze was bloody expensive (although I now have enough to last me for the next 50 years at current rate) so in hindsight I probably should have gone for Pumaracing's option of machining an adaptor for the crank and using a TD5 spigot as it would have saved me 70 or 80 quid. Having said that at least I've got peace of mind that it's all as it should be.

I've kept the design on file here and I do have enough Oilite bronze of appropriate size to last me a lifetime so if anyone with a 2.8i Defender is looking for one and stumbles across this thread then drop me a PM! Happy to knock one up for the cost of the length of bronze and some more beer for Ian!

Edited by The Wookie on Thursday 5th June 10:56

Hi there, I know it's a bit of s longshot but I'm looking to do a M52 conversion on my defender, a few bits of confusion relate to the sprigot bearing.. do you still have access to material to produce these?

Many thanks
Tom

[The Wookie]

I think so probably still sat in my desk at work! I can give you the drawing I did for it too if it helps? Ping the thread in the new year to remind me if you haven’t heard from me!