H22 alternator bearing replacement

Scott560 · Post by **Scott560** » Wed Jul 24, 2024 6:48 pm

I replaced both the bearings in my alternator today. The Alternator was replaced a while ago with a Lucas refurbed unit purchased from euro car parts but it had started to make a droning noise at start up and low speeds.

For me, the removal and refitting of the alternator is harder than swapping the bearings. Getting the alternator out requires small hands, and exactly the right length/depth sockets. Make sure you have a magnet on a stick.

Decided to write it down and take pictures as I went.

Remove Alternator:

1) Disconnect battery terminals (10mm), tuck out the way.
2) pull back the rubber boot, depress the tang, and remove the multiplug from the alternator
3) using a 10mm spanner and a hammer (or impact) , undo the main battery terminal wire from the post. This might be very stiff. Use some penetrating fluid. Be careful not to damage the nut/wire/threaded part.
4) remove the orange ABS multiplug from its bracket to give you extra space. Pull up on the PS reservoir so it can be moved around.
5) Using a long 14mm socket, loosen the top alternator bolt (you will struggle to see the bolt head, loosen it enough so you can then undo it by hand)

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6)Using a slightly smaller length 13mm socket, you can access the worst nut of all. It is directly underneath the alternator. Loosen it with the ratchet, then unwind and recover it by hand. You can then pull the bolt out from the other side (underneath the alternator, from the manifold side)

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You can see the non headed bolt right at the bottom right of this picture, you can simply pull it out once you have removed the nut.

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Top bolt in the middle, lower one flanking it.

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7) I then removed the the tension adjuster bracket (left most of the 10mm bolts pointing towards the front of the car, no pic sorry). The alternator should be loose enough at this point to push it towards the block, relieving belt tension. You can then slip the belt out of the way (tight fit if you left PS pump in place).

8 ) using a pry bar, wedge out the alternator from its top bracket mounting point. The alternator can then be manipulated and drawn out the manifold side.

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Rebuild Alternator:

1) I didn't have to be too careful with my pulley as I wanted to replace it with the genuine Honda one. Using an impact gun and a 22mm socket I whizzed it off. IF you plan to reuse the pulley, try holding the pulley in a way that wont damage it.

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2) Flip it around, and start to disassemble. Remove the rear cover with small 8 or 10mm nuts, various screws etc. Then you can unscrew the stator windings from the diode pack. Be sure to remove the rubber insulators and keep them safe.

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3) Just when you thought the job was getting harder, it got easier. Splitting the alternator housing just required a few light taps with a hammer to shock it all loose. If yours is 25 years old then you might have more swearing involved, but be careful the housing it soft aluminium and doesn't want a good bashing, just tapping on the housing and protruding pulley shaft will eventually split it into 3 parts.

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New post to follow (max 10 files upload per post).

Scott560 · Post by **Scott560** » Wed Jul 24, 2024 7:04 pm

4) Unscrew the front bearing retaining plate (4 screws). Be careful they are not standard heads but JIS , so take care not to strip them. The bearing very easily taps out from the other side with a hammer and a socket. The socket doesn't have to fit perfectly on the outer race as we are not keeping the bearings. You could use a stake or anything to pop it out really. It didn't put up a fight at all.

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5) Check the old bearing and new bearing are the same size before trying to refit it. new one on the left. Old bearing had play. Hard to detect at first, but audible when shaking it.

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6) Fit the new bearing, tapping it into place using the old bearing as the perfectly sized brace/drift. Once it had got in and centred, it practically fell into place. I had heated the housing up a little with a hot air gun and also put the bearing in the freezer to avoid unnecessary pain but this is almost certainly not needed. Refit the bearing plate and 4 screws. I used a manually operated hammer/impact tool to torque up the screws, as I couldn't grip the alternator in my small vice.

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7) Probably the hardest part, removing the rear bearing from the rotor shaft. The bearing is press fit on the shaft. I tried gripping the bearing in the vice and tapping the shaft with a drift, but it wouldn't budge. My 3 legged puller was a little too big to to fit (both under the bearing, and without hitting the cooling fan fins). In the end I used my 2 smallest spanners, and pulled upwards towards me. When centralised, the bearing started to lift off without much effort. Gradually replacing the smaller spanners with larger ones (which were thicker) I was table to get it off. Be careful not to damage the copper slip rings. Check bearings match before refitting.

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8 ) using an appropriate 17mm deep socket (so as not to foul the shaft), drive on the inner race of the new bearing. Be careful not to hit too forcefully, depending how you have the rotor mounted, you may be damaging the cooling fins on the reverse. Be prepared to bend them back a little if needed. The bearing sits all the way flush down the shaft, no need to measure anything, just drive it on until it stops.

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9) Give the housing where the bearings sit a bit of a clean up, and start to reassemble. You will need to depress the brushes in the regulator to slip it back on over the copper slip rings. Be sure to refit the insulators for the stator windings. Remember there is a wavy preload washer in the alternator housing, be sure to make sure its correctly located. new pulley and nut were fitted, used the impact to do it up (otherwise you will need a deep 22mm ring spanner to do it up whilst using another spanner to hold the shaft still.)

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Refitting is the reverse of removal - it's a bit of a pain!

Scott560 · Post by **Scott560** » Wed Jul 24, 2024 7:07 pm

Amayama parts list and prices for both bearings and pulley and nut.

https://www.amayama.com/en/part/honda/31111pt0003
Honda 31111-PT0-003 - BEARING, RR. GENERATOR
1 5.76

https://www.amayama.com/en/part/honda/31114pt0013
Honda 31114-PT0-013 - BEARING, FR. GENERATOR
1 6.14

https://www.amayama.com/en/part/honda/31141p13003
Honda 31141-P13-003 - PULLEY
1 15.66

https://www.amayama.com/en/part/honda/31142pd1004
Honda 31142-PD1-004 - NUT, PULLEY LOCK
1 1.07

Post by **Drax** » Thu Jul 25, 2024 9:02 am

fantastic write-up thank you

rare to see something as detailed as this these days.

can i ask, are these parts for a 5G UKDM alternator i guess? as im pretty sure JDM is different somehow (maybe not internally??) plus im again guessing H22 4G is again different...?

cheers!

Scott560 · Post by **Scott560** » Thu Jul 25, 2024 9:38 am

This was for 5th gen ukdm, I suspect the bearings are the same for all 5th gen. Pulley is different depending on engine.

4th gen couldn't say, the parts listing in is on amayama, suspect the whole process is very similar, I think it's only the regulators that differ on the JDM ones...