[rtkraken]

Hey Guys,
Just finished re-securing the end bushing that sits behind the brushes in the end bell of the compreoosr motor. Rough noisy running and a failed thermal switch lead me to tear it down to see what could be done. What I learned was surprising.
There's a composite? ring that may serve to ease assembly by holding the brushes apart during assembly and then lives in the compressor from then on. It eventually wears down the crimp indents that secure the bushing cage plate into the housing. When this happens the bushing cage plate slips out and allows the bushing, plate, and ring to wallow free, eventually damaging the connections on the backside of the brush card.
I cleaned up the bush and fittings, re-oiled the felt, and re-pressed the whole assembly back into the end plate then gently peened over the edges, in four places, to re-secure the bush cage. The bush is free to align itself in it's cage/socket, but won't freely spin. I didn't include the composite ring in the reassembly. Thus eliminating the chance of future wear and failure. :thumb:

Here are some photos of the project:

Bad bushing and plate, loose and free to travel out of center.

Drilled press fit pins and removed brush card.

Another shot of loose bush and plate with brush card removed.

Bush components. Bush, oil felt, cage plate, composite ring.

Bush cleaned, oiled, installed with oiled felt, and cage plate pressed and peened into place.

Back together. (Yeah, I broke off one of the fitting screws :doh: , it'll hold.)

Commutator...

Holdong brush out as you "walk" the end bell back onto the commutator/shaft.

Ohm reading across brushes after assembly. New brushes.

 

[shupack]

There's a composite? ring that may serve to ease assembly by holding the brushes apart during assembly

That's it! I've been wondering what the hell that ring does for years, it may be just that.

Except the ring is held in the clamps with the bearing retainer on ones that havn't fallen apart, so it may not be high enough... maybe that's not it.... it's still useless as far as I can tell.

Those are great photos, I've been meaning to shoot some for my instructions page, can I use yours?

 

[rtkraken]

Except the ring is held in the clamps with the bearing retainer on ones that havn't fallen apart, so it may not be high enough... maybe that's not it.... it's still useless as far as I can tell.

Those are great photos, I've been meaning to shoot some for my instructions page, can I use yours?

Hmmm, oh well so much for that guess. Funny, it worked pretty well holding the brushes apart for assembly before I tore things down and removed it. Must just serve as some sort of thrust bearing, but everything I've read said it was useless. Didn't realize you were into this end of the assembly. Please feel free to copy and use any of these photos. It what it's all about. :thumb:

 

[viperover]

Regertably I have issues rebuilding these compressors now, done loads and still going fine but I've had a couple of returns
Seems it depends how old they are, newer compressors seem to be lasting, failures are slow running which means brush spring force too low..

Personaly I advise on the larger compressor mod, best move ever by far

 

[rtkraken]

Personaly I advise on the larger compressor mod, best move ever by far

Yup, this was a learning experience for me, that only cost me a few screws. So what's all the secrecy about the cheaper, bigger, and better R3470 pump? Where can I get one and what sage advice do you have on putting one in? Common, hook us up!

 

[viperover]

Personaly I advise on the larger compressor mod, best move ever by far

Yup, this was a learning experience for me, that only cost me a few screws. So what's all the secrecy about the cheaper, bigger, and better R3470 pump? Where can I get one and what sage advice do you have on putting one in? Common, hook us up!

Hi I cant hook you up with a compressor as Im in South Africa, its that place on the southern tip of Africa where we have roaring Lions, charging Elephants, Chetahs that can out run a fast car on pull away, Lepards that hide in trees.....
anyway..

The larger compressor is the same as the original, visably larger and it fits the EAS box but front bracket on OEM pump is required with 2 additional holes to be drilled using the gasket as a template.
Cylinder head needs inlet port to be blanked off and 2 holes drilling to allow for intake air to travel as per OEM unit
Rear bracket that comes with the larger compressor requires rebending and rear support bracket on the valve block bent down and thread stub straightened again, usualy if done right there is no need to modify the top cover

From start to finish its around a hours job and is not to overly complex
Sadly Im not gearing up for sales on these units as Im fully occupied repairing Rangies.........all the time
Im sure somone here will steer you in the right direction where to get one

Lastly I will be updating my blog on the compressor mod in more detail during the week (time permitting) along with a useful and important EAS valve block mod, its to do with correcting air bypassing diaphragm if its still good and have discovred a cure that works

 

[shupack]

here:
http://www.rover-renovations.com/Range-Rover-Air-Compressor-Aftermarket-p/anr3731a.htm

BUT, the factory is moving south, away from the snow, and they don't have any right now, so I don't have any unfortunately.

The mods are easy, and outlined on the instructions pages, linked at the bottom of the description.

 

[rtkraken]

Thanks Viperover and Dennis. I started googling and eventually found your information on the upgrade. I'm curious, after doing a bit of research on Thomas' website it appears a 307 or 309 series compressor may work. Are these the guy's that are moving at present. (first they move south, the next move is off-shore... / )

 

[shupack]

yes, it's thomas. the OEM LR compressor is the 314 (I think..) so the 309 would be a step backwards, the 327 is what I use, the important part is the second number, 56/12. not sure what they stand for (bore/stroke maybe?) , but it determines the pressure and flow of the final output. A generic air-ride place is selling the 327, but in the 50/12 model, rated to a lower pressure. I bought one to check on (since it was only listed as the 327) and the piston is significantly larger diameter, so higher flow but much lower pressure, not good for the RR, since most of it's life will be spent going from 130 to 140psi.

 

[viperover]

yes, it's thomas. the OEM LR compressor is the 314 (I think..) so the 309 would be a step backwards, the 327 is what I use, the important part is the second number, 56/12. not sure what they stand for (bore/stroke maybe?) , but it determines the pressure and flow of the final output. A generic air-ride place is selling the 327, but in the 50/12 model, rated to a lower pressure. I bought one to check on (since it was only listed as the 327) and the piston is significantly larger diameter, so higher flow but much lower pressure, not good for the RR, since most of it's life will be spent going from 130 to 140psi.

Thought I'd add this link for your info, seems its flow rate and slight difference in pressure, you had me worried as I only do the 327 50/12

The 56/12 is rated at 10.3 where as the 50/12 is rated at 10.4 but then they seem to have things mixed up, note that 10.4 bar is 150psi where it should rear 150.1psi, 10.3 should 150psi....but it works
There's no benefit using the larger 337 as I have and now prefer the 327, pump up time with empty air tank is usually 4-5 mins depending on temp etc as we are high up in the clouds

http://www.gd-thomas.com/productList.aspx?id=9870&tp=p

 

[rtkraken]

OK it's been a few years since I made this repair and it failed. The bushing hold down plate shattered, maybe too brittle for the tension placed on it from peening the outer edge. Oh well, it lasted a few years and 30K miles. So, not to be beaten, I once again tried something new and different. The recess in the end bell that the bearing fits into measures 23mm wide by approx. 6mm deep. The rotor shaft measures just a tad under 8mm in diameter. I started looking for a bearing that would fit these dimensions and the closest available just happens to be a widely available skate board bearing size (608ZZ) It measures 22 x 8 x 7. So I ran down to Wallymart and grabbed a skateboard. (it would have been cheaper to just order one on line and wait, but I had to prove it could be done with local resources) Once I returned home I unscrewed one of the wheel and popped a bearing out (each wheel has two) and began checking fit and figuring out how to secure it in the end bell. Well, it turns out that a piece of flashing is just the right thickness to cut a thin circumferential strip out of and place it around the perimeter of the recess and press the bearing in with a 15mm socket. Nice and tight! So reassembled the end bell (modified as previously posted here) and, I'll be ****ed, it works! Back on the road with a few hours of work and a $3.00 bearing. No telling how it'll last, but it runs smooth for now.

 

[John W]

Very interesting,as you say I wonder how long the bearing will last running in a hotter enviroment.

 

[rtkraken]

Yes, the biggest weakness I see is the rotor shaft fit up in the inner race. It's just loose enough to allow it to spin in the inner race. (about the same fit up as the original bronze bushing) I would have rather had it press fit onto the shaft, but only one race can be pressed in and allow assembly. So far so good after a day of running errands.

 

[Jos Geuze]

Hi

To prevent the bearing from movement inside the bearing race, you could use loctite and glue it to the shaft. You might need to use the retaining liquid for high temperatures.

Regards

Jos

 

[britpara]

Any news on how the mods are holding up? I've just replaced the seal and liner because the compressor was noisy but although it now pumps better, its still noisy. Adding rubber gaskets above and below the mountings helped but I'm thinking it could be the same as you described previously. I had a quick look and removed the plastic while I was in there. The bushing seems straight enough - would a few drops of gear oil help to quieten things down? Or is it time for a new compressor????

 

[rtkraken]

Any news on how the mods are holding up? I've just replaced the seal and liner because the compressor was noisy but although it now pumps better, its still noisy. Adding rubber gaskets above and below the mountings helped but I'm thinking it could be the same as you described previously. I had a quick look and removed the plastic while I was in there. The bushing seems straight enough - would a few drops of gear oil help to quieten things down? Or is it time for a new compressor????

Unfortunately I got word from home, while overseas, that the compressor had failed. I opted for a new compressor since further repair was out of my family's capability. They were able to swap compressors successfully. The old compressor is waiting for my return home and subsequent tear down for investigation. The commutator looked pretty beat when I last had it apart so I suspect that was the failure. I got a couple extra years of daily use life outta mine by simply playing around with the bearings. It all depends on your tolerance for experimentation. When I get home, I'll have a look at the skateboard bearing mod and see if it held. I was pretty pleased with that one and was in hopes that it would out last the motor elements. TBD.