How do you get the pins out of the rotors on a 4-71 blower?
Moderator: phpBB2 - Administrators
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
How do you get the pins out of the rotors on a 4-71 blower?
Looks like they can only go 1 way---- in! I assume they knock in then you slide the shaft out and drop the loose pins out- but dont want to try it without some re-assurance!
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
The original pins are tapered and driven in, then the hole is peened over to eliminate the unlikely event that the pin starts to back out.
If there is no pin there then ream it and fit another pin. If the pin is there but driven in deep then I would leave well alone, just make sure the hole is peened over. One of the upgrades we do to GMC blowers is to double pin the rotors to the shafts, so now would be an ideal time to do that.
I have some spare core plugs for the end of the rotors.
If there is no pin there then ream it and fit another pin. If the pin is there but driven in deep then I would leave well alone, just make sure the hole is peened over. One of the upgrades we do to GMC blowers is to double pin the rotors to the shafts, so now would be an ideal time to do that.
I have some spare core plugs for the end of the rotors.
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
Thanks Nigel, the plug or perhaps plugs that have dropped in are the ones in the ends of the shaft not the ones in the actual rotors, though I would like a spare one of those too- could you let me know how much for 1 spare rotor plug and 2 spare shaft plugs with the other gear (gaskets etc) I have emailed you about?
Thanks Tom.
Thanks Tom.
To be honest Tom, until you mentioned it, I wasn't aware there was a core plug in the shaft, but you are right and its fitted from the inside !!!
I would not try to remove the shaft from the rotor.....its not going to slip out as you say, it will either be an interference press fit or may even have been cast into the rotor at the foundry. If you can get the old plug out then great, as it will obviously rattle around in the hollow rotor casting.
I wouldn't worry about not having a plug in there so long as the rotor is sealed at the 6 core plugs at the end and the shaft pins.
I've e-mailed requested prices to you.
I would not try to remove the shaft from the rotor.....its not going to slip out as you say, it will either be an interference press fit or may even have been cast into the rotor at the foundry. If you can get the old plug out then great, as it will obviously rattle around in the hollow rotor casting.
I wouldn't worry about not having a plug in there so long as the rotor is sealed at the 6 core plugs at the end and the shaft pins.
I've e-mailed requested prices to you.
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
No reason why you can't run the rear bearings in an oil bath.......its just not normally done. All aftermarket GM blowers are built with heavy duty bearing plates, and the rears, without exception, have no provision for an oil bath. The oil in the front cover is primarily to lubricate the gears.
One more thing you will need to be aware of is that there are oilways in the stock bearing plates which lead to holes in the blower case which will need threading and plugging.
One more thing you will need to be aware of is that there are oilways in the stock bearing plates which lead to holes in the blower case which will need threading and plugging.
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact: