Alternator rebuilding...
11-05-2013, 07:20 PM
#1
AudiWorld Senior Member
Thread Starter
Bosch 150 Amp Alternator Rebuild...
There are some guides on how to do this for Bosch alternators. Some minor differences do exist with a 150 Amp alternator used on C5 4.2
This is no guide but more like some pointers for those willing to do this themselves. This rebuild should cost approx. $60.00, YMMV.
Disclaimer: I am not responsible; use this info as you wish.
Ok, It all started with a rattling like sound that has gotten worse when stopping at a light while transmission in Drive. Having a helper put the car in drive while pressing brakes, crawled under and pushed alternator with hand and sound goes away. Tightened bolts but no use. Pulled belt off, reseated alternator, no use. The problem lies in bad/worn bearings.
Parts you'd need:
1) 6203 Bearing 2 side Rubber Sealed(17mm-ID X 40mm-OD X 17mm-Width) ~ $10.00
2) 6304 Bearing 2 side Rubber Sealed(17mm-ID X 52mm-OD X 17mm-Width) ~ $30.00
3) Bosch Slip Ring (see attached pic) ~ $10.00
4) Bosch Brush kit ~ $5.00
5) 4 M4-.7x20mm Socket head bolts (Home Depot) ~ $1.50
Note: Don't buy cheap bearings. 6304 is a special bearing -mainly due to its uncommon 52MM Outer Diameter with 17mm ID. 6203 seems to be a common bearing. Buy Fafnir or *** or some well established brand and not some generic. You want quality bearings here. Also, get only rubber double sealed bearings. Metal seal sounds more durable but in fact, will leak out and go bad quickly in alternator's exposed environment.
The guide itself is very good and that's what got me interested in doing this job. All credit for the guide goes to the author. Link: http://www.rangerovers.net/repairdet...haltrepair.htm
C5 Outline:
1) Disconnect battery - or + (whatever mood you're in).
2) Remove bolt for fastener that holds the A/C line coming from compressor attached to the block by oil pan, near alternator. This will allow you to slide ratchet in easily to turn belt tensioner as well as to remove the alternator.
3) Release tension on ribbed belt by turning belt tensioner CW and slide belt off alternator.
4) Remove all wiring attached to alternator and pull out the air vent at alternator's base -no need to remove it from carrier.
5) Remove alternator bolts and slide it out.
6) Follow the guide to remove the nut from the shaft. (lesson learned, don't hold pulley with adj. pliers etc. It is a very soft metal and you'll ruin it easily and it's not easy to find either.)
-) Remove pulley, bolts, air vent base etc.. and using sockets and pulley pullers, (improvise) separate both halves and pull shaft out.
----) Original bolts behind pulley are Phillips head and mine were stubborn and stripped. So, I just drilled the heads out and used hole punch to push them out along with the bearing plate. Replace them with excellent Hex socket head bolts from Home Depot.
-) Using pulley puller, pull the rear bearing out and "punch out" the bigger 6304 from the front-half casing.
-) Regulator - Use soldering iron and De-solder the carbon brushes (spring loaded!). On the new brush, remove protective sleeve, slide in old spring and slide the brush and wire through the contact. The brush's base should be barely visible outside; solder it at the back of metal contact. NEVER apply any grease, oil or any lubricant to carbon brushes or slip ring!!! When running, this will cut the slip ring very deep before you can say, "slip ring". In fact, I suggest cleaning the copper rings with alcohol or acetone. Don't mess with brushes period. They are just like pencil lead and could break easily.
-) Pry/disconnect the alternator's winding wires at the base of slip ring. Make sure you do this carefully. Twist, Dremel, hole punch, whatever to get the old slip ring off -WITHOUT- bending the shaft (its very small in dia.)
-) Clean it, slide new slip ring on, rubber mallet etc. to seat it to base. Match the NOTCH. Solder the wires to slip ring contacts.
-) Slide new 6203 bearing, using spark plug socket or similar, hammer it in gently all the way to the slip ring's base.
-) With C-clamp or a bearing press, press in 6304 bearing to the front casing -always apply pressure only to the ring that is direct contact to mounting surface.
7) Check for continuity on slip ring and assemble it all together. If you have a ride, take the alternator to nearby AutoZone or AdvanceAuto parts store - they'll do a free test. Mine passed without any issues.
8) Mounting alternator is reversal of removal. Slide belt back on (check and make sure the belt ribs are aligned on all pulleys properly and the belt has not slipped or laying sloppy on idlers) , fasten A/C line, plug vent back in and enjoy another 100K miles of a "new" alternator.
This is no guide but more like some pointers for those willing to do this themselves. This rebuild should cost approx. $60.00, YMMV.
Disclaimer: I am not responsible; use this info as you wish.
Ok, It all started with a rattling like sound that has gotten worse when stopping at a light while transmission in Drive. Having a helper put the car in drive while pressing brakes, crawled under and pushed alternator with hand and sound goes away. Tightened bolts but no use. Pulled belt off, reseated alternator, no use. The problem lies in bad/worn bearings.
Parts you'd need:
1) 6203 Bearing 2 side Rubber Sealed(17mm-ID X 40mm-OD X 17mm-Width) ~ $10.00
2) 6304 Bearing 2 side Rubber Sealed(17mm-ID X 52mm-OD X 17mm-Width) ~ $30.00
3) Bosch Slip Ring (see attached pic) ~ $10.00
4) Bosch Brush kit ~ $5.00
5) 4 M4-.7x20mm Socket head bolts (Home Depot) ~ $1.50
Note: Don't buy cheap bearings. 6304 is a special bearing -mainly due to its uncommon 52MM Outer Diameter with 17mm ID. 6203 seems to be a common bearing. Buy Fafnir or *** or some well established brand and not some generic. You want quality bearings here. Also, get only rubber double sealed bearings. Metal seal sounds more durable but in fact, will leak out and go bad quickly in alternator's exposed environment.
The guide itself is very good and that's what got me interested in doing this job. All credit for the guide goes to the author. Link: http://www.rangerovers.net/repairdet...haltrepair.htm
C5 Outline:
1) Disconnect battery - or + (whatever mood you're in).
2) Remove bolt for fastener that holds the A/C line coming from compressor attached to the block by oil pan, near alternator. This will allow you to slide ratchet in easily to turn belt tensioner as well as to remove the alternator.
3) Release tension on ribbed belt by turning belt tensioner CW and slide belt off alternator.
4) Remove all wiring attached to alternator and pull out the air vent at alternator's base -no need to remove it from carrier.
5) Remove alternator bolts and slide it out.
6) Follow the guide to remove the nut from the shaft. (lesson learned, don't hold pulley with adj. pliers etc. It is a very soft metal and you'll ruin it easily and it's not easy to find either.)
-) Remove pulley, bolts, air vent base etc.. and using sockets and pulley pullers, (improvise) separate both halves and pull shaft out.
----) Original bolts behind pulley are Phillips head and mine were stubborn and stripped. So, I just drilled the heads out and used hole punch to push them out along with the bearing plate. Replace them with excellent Hex socket head bolts from Home Depot.
-) Using pulley puller, pull the rear bearing out and "punch out" the bigger 6304 from the front-half casing.
-) Regulator - Use soldering iron and De-solder the carbon brushes (spring loaded!). On the new brush, remove protective sleeve, slide in old spring and slide the brush and wire through the contact. The brush's base should be barely visible outside; solder it at the back of metal contact. NEVER apply any grease, oil or any lubricant to carbon brushes or slip ring!!! When running, this will cut the slip ring very deep before you can say, "slip ring". In fact, I suggest cleaning the copper rings with alcohol or acetone. Don't mess with brushes period. They are just like pencil lead and could break easily.
-) Pry/disconnect the alternator's winding wires at the base of slip ring. Make sure you do this carefully. Twist, Dremel, hole punch, whatever to get the old slip ring off -WITHOUT- bending the shaft (its very small in dia.)
-) Clean it, slide new slip ring on, rubber mallet etc. to seat it to base. Match the NOTCH. Solder the wires to slip ring contacts.
-) Slide new 6203 bearing, using spark plug socket or similar, hammer it in gently all the way to the slip ring's base.
-) With C-clamp or a bearing press, press in 6304 bearing to the front casing -always apply pressure only to the ring that is direct contact to mounting surface.
7) Check for continuity on slip ring and assemble it all together. If you have a ride, take the alternator to nearby AutoZone or AdvanceAuto parts store - they'll do a free test. Mine passed without any issues.
8) Mounting alternator is reversal of removal. Slide belt back on (check and make sure the belt ribs are aligned on all pulleys properly and the belt has not slipped or laying sloppy on idlers) , fasten A/C line, plug vent back in and enjoy another 100K miles of a "new" alternator.
Last edited by tester123; 11-06-2013 at 08:38 AM.
11-06-2013, 07:06 AM
#3
AudiWorld Super User
There are some guides on how to do this for Bosch alternators. Some minor differences do exist with a 150 Amp alternator used on C5 4.2
This is no guide but more like some pointers for those willing to do this themselves. This rebuild should cost approx. $60.00, YMMV.
Disclaimer: I am not responsible; use this info as you wish.
Ok, It all started with a rattling like sound that has gotten worse when stopping at a light while transmission in Drive. Having a helper put the car in drive while pressing brakes, crawled under and pushed alternator with hand and sound goes away. Tightened bolts but no use. Pulled belt off, reseated alternator, no use. The problem lies in bad/worn bearings.
Parts you'd need:
1) 6203 Bearing 2 side Rubber Sealed(17mm-ID X 40mm-OD X 17mm-Width) ~ $10.00
2) 6304 Bearing 2 side Rubber Sealed(17mm-ID X 52mm-OD X 17mm-Width) ~ $30.00
3) Bosch Slip Ring (see attached pic) ~ $10.00
4) Bosch Brush kit ~ $5.00
Note: Don't buy cheap bearings. 6304 is a special bearing -mainly due to its uncommon 52MM Outer Diameter with 17mm ID. 6203 seems to be a common bearing. Buy Fafnir or *** or some well established brand and not some generic. You want quality bearings here. Also, get only rubber double sealed bearings. Metal seal sounds more durable but in fact, will leak out and go bad quickly in alternator's exposed environment.
The guide itself is very good and that's what got me interested in doing this job. All credit for the guide goes to the author. Link: http://www.rangerovers.net/repairdet...haltrepair.htm
C5 Outline:
1) Disconnect battery - or + (whatever mood you're in).
2) Remove bolt for fastener that holds the A/C line coming from compressor attached to the block by oil pan, near alternator. This will allow you to slide ratchet in easily to turn belt tensioner as well as to remove the alternator.
3) Release tension on ribbed belt by turning belt tensioner CW and slide belt off alternator.
4) Remove all wiring attached to alternator and pull out the air vent at alternator's base -no need to remove it from carrier.
5) Remove alternator bolts and slide it out.
6) Follow the guide to remove the nut from the shaft. (lesson learned, don't hold pulley with adj. pliers etc. It is a very soft metal and you'll ruin it easily and it's not easy to find either.)
-) Remove pulley, bolts, air vent base etc.. and using sockets and pulley pullers, (improvise) separate both halves and pull shaft out.
-) Using pulley puller, pull the rear bearing out and "punch out" the bigger 6304 from the front-half casing.
-) Regulator - Use soldering iron and De-solder the carbon brushes (spring loaded!). On the new brush, remove protective sleeve, slide in old spring and slide the brush and wire through the contact. The brush's base should be barely visible outside; solder it at the back of metal contact. NEVER apply any grease, oil or any lubricant to carbon brushes or slip ring!!! While running, this will cut slip ring very deep before you can say "slip ring".
-) Pry/disconnect the alternator's winding wires at the base of slip ring. Make sure you do this carefully. Twist, Dremel, hole punch, whatever to get the old slip ring off -WITHOUT- bending the shaft (its very small in dia.)
-) Clean it, slide new slip ring on, rubber mallet etc. to seat it to base. Match the NOTCH. Solder the wires to slip ring contacts.
-) Slide new 6203 bearing, using spark plug socket or similar, hammer it in gently all the way to the slip ring's base.
-) With C-clamp or a bearing press, press in 6304 bearing to the front casing -always apply pressure only to the ring that is direct contact to mounting surface.
7) Check for continuity on slip ring and assemble it all together.
8) Mounting alternator is reversal of removal. Slide belt back on, fasten A/C line, plug vent back in and enjoy another 100K miles of a "new" alternator.
This is no guide but more like some pointers for those willing to do this themselves. This rebuild should cost approx. $60.00, YMMV.
Disclaimer: I am not responsible; use this info as you wish.
Ok, It all started with a rattling like sound that has gotten worse when stopping at a light while transmission in Drive. Having a helper put the car in drive while pressing brakes, crawled under and pushed alternator with hand and sound goes away. Tightened bolts but no use. Pulled belt off, reseated alternator, no use. The problem lies in bad/worn bearings.
Parts you'd need:
1) 6203 Bearing 2 side Rubber Sealed(17mm-ID X 40mm-OD X 17mm-Width) ~ $10.00
2) 6304 Bearing 2 side Rubber Sealed(17mm-ID X 52mm-OD X 17mm-Width) ~ $30.00
3) Bosch Slip Ring (see attached pic) ~ $10.00
4) Bosch Brush kit ~ $5.00
Note: Don't buy cheap bearings. 6304 is a special bearing -mainly due to its uncommon 52MM Outer Diameter with 17mm ID. 6203 seems to be a common bearing. Buy Fafnir or *** or some well established brand and not some generic. You want quality bearings here. Also, get only rubber double sealed bearings. Metal seal sounds more durable but in fact, will leak out and go bad quickly in alternator's exposed environment.
The guide itself is very good and that's what got me interested in doing this job. All credit for the guide goes to the author. Link: http://www.rangerovers.net/repairdet...haltrepair.htm
C5 Outline:
1) Disconnect battery - or + (whatever mood you're in).
2) Remove bolt for fastener that holds the A/C line coming from compressor attached to the block by oil pan, near alternator. This will allow you to slide ratchet in easily to turn belt tensioner as well as to remove the alternator.
3) Release tension on ribbed belt by turning belt tensioner CW and slide belt off alternator.
4) Remove all wiring attached to alternator and pull out the air vent at alternator's base -no need to remove it from carrier.
5) Remove alternator bolts and slide it out.
6) Follow the guide to remove the nut from the shaft. (lesson learned, don't hold pulley with adj. pliers etc. It is a very soft metal and you'll ruin it easily and it's not easy to find either.)
-) Remove pulley, bolts, air vent base etc.. and using sockets and pulley pullers, (improvise) separate both halves and pull shaft out.
-) Using pulley puller, pull the rear bearing out and "punch out" the bigger 6304 from the front-half casing.
-) Regulator - Use soldering iron and De-solder the carbon brushes (spring loaded!). On the new brush, remove protective sleeve, slide in old spring and slide the brush and wire through the contact. The brush's base should be barely visible outside; solder it at the back of metal contact. NEVER apply any grease, oil or any lubricant to carbon brushes or slip ring!!! While running, this will cut slip ring very deep before you can say "slip ring".
-) Pry/disconnect the alternator's winding wires at the base of slip ring. Make sure you do this carefully. Twist, Dremel, hole punch, whatever to get the old slip ring off -WITHOUT- bending the shaft (its very small in dia.)
-) Clean it, slide new slip ring on, rubber mallet etc. to seat it to base. Match the NOTCH. Solder the wires to slip ring contacts.
-) Slide new 6203 bearing, using spark plug socket or similar, hammer it in gently all the way to the slip ring's base.
-) With C-clamp or a bearing press, press in 6304 bearing to the front casing -always apply pressure only to the ring that is direct contact to mounting surface.
7) Check for continuity on slip ring and assemble it all together.
8) Mounting alternator is reversal of removal. Slide belt back on, fasten A/C line, plug vent back in and enjoy another 100K miles of a "new" alternator.
Good show. FWIW, I had to replace the entire VR on my 2K4.2A6 V8 rather than replace the brushes. The VR had the brush(s) pigtails spot welded to the VR contacts rather than the old crimped bushing attachment I was very familiar with on Bosch alternators for Volvos and Saabs. On those alternator VRs I was able to crimp new bushings onto new pigtails/brushes and solder them onto the VR (belt and suspenders…use silver or higher-temp electrical solder) but on the 4.2 alternators it doesn't work.
11-06-2013, 07:12 AM
#4
AudiWorld Super User
IF you can get the long bolt out without service position, good luck.
11-06-2013, 07:28 AM
#5
AudiWorld Senior Member
Thread Starter
Simple test: hold inner ring with left hand and push/twist outer ring. If there is a significant play, it is bad. A very minute-to-no play is normal. I told him that it looks wobbly and asked for another. This time he got me a brand new one with sealed package. @$30 for a simple bearing, you better make sure it is new.
The brush kit and slip ring can be found from same rebuild shops but Bosch slip ring -for this particular model- is difficult to find and I don't know if other Bosch slip rings are same dimensions. Not being able to drive for nearly 2 days, I ended up getting an aftermarket type found at the local shop. I updated the thread with pic for dimensions on slip ring. eBay might be the best bet here if you can't find locally.
Service position? No, you don't have to. Just loosen the A/C line fastener and you'll have all the room to pull it out. Just don't tug on the aluminum line too hard.
11-06-2013, 07:35 AM
#6
AudiWorld Senior Member
Thread Starter
On my 2K4.2A6 I had to put it in service position to get the long alternator bolt out. It's not necessary to put it in service position to get the serp belt tensioner locked…just pull down on the serp belt to collapse the tensioner and use your other hand to insert a 4? mm allen wrench into the center of the tensioner hex…it stops the tensioner from moving and the serp belt can be removed from the alternator.
IF you can get the long bolt out without service position, good luck.
IF you can get the long bolt out without service position, good luck.
For alternator, use the 3/8" ratchet with appropriate Hex socket for long bolt and a 13mm for the short bolt to block. I found that there is enough clearance for long bolt to come out without removing anything else.
Last edited by tester123; 11-06-2013 at 07:37 AM.
11-06-2013, 07:49 AM
#7
AudiWorld Senior Member
Thread Starter
Good show. FWIW, I had to replace the entire VR on my 2K4.2A6 V8 rather than replace the brushes. The VR had the brush(s) pigtails spot welded to the VR contacts rather than the old crimped bushing attachment I was very familiar with on Bosch alternators for Volvos and Saabs. On those alternator VRs I was able to crimp new bushings onto new pigtails/brushes and solder them onto the VR (belt and suspenders…use silver or higher-temp electrical solder) but on the 4.2 alternators it doesn't work.
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11-06-2013, 01:34 PM
#8
AudiWorld Super User
On my 2K4.2A6 I had to put it in service position to get the long alternator bolt out. It's not necessary to put it in service position to get the serp belt tensioner locked…just pull down on the serp belt to collapse the tensioner and use your other hand to insert a 4? mm allen wrench into the center of the tensioner hex…it stops the tensioner from moving and the serp belt can be removed from the alternator.
IF you can get the long bolt out without service position, good luck.
IF you can get the long bolt out without service position, good luck.
11-06-2013, 01:37 PM
#9
AudiWorld Super User
From the looks of it, I thought the same. Just for kicks, I had the Weller Iron turned up to 760°F and the solder around the small "tube" like post melted and shot the old brush out.. had to search for spring but that's another matter. Try it, if doesn't work, you can always drill it out.
11-06-2013, 01:46 PM
#10
AudiWorld Super User
Yes, the tensioner is a beatch, use a long wrench if pulling the serp belt doesn't work!
LOL.