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luvthemvws
Samba Member
Joined: February 13, 2012
Posts: 117
Location: Middle of nowhere
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 Posted: Sun Jul 20, 2014 8:11 am Post subject: How many miles from a Richmond, T1, 4.86 Gear? |
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This will be in a swing axle, mostly street driven (with some dune running) Baja.
The engine is a stock, T4, 2 liter that runs fine and I have no intention of changing it.
I know the 4.86 is inherently weaker, but I am not an abusive driver and I like how it keeps my engine in it's sweet spot.
I understand that the 4.86 is made from 9310 steel, which is slightly "softer" than a normal, street, gear set. This to compensate for the tiny pinion tooth configuration and give it better shock resistance.
What I wonder is: How many street miles can I expect from a properly set up gear set?
I have heard horror stories of just a couple thousand miles.
I don't mean breakage, just wear.
Should I just expect to replace it regularly, like I would for a racing/competition, preventative maintenance situation? |
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oldschool5er
Samba Member
Joined: May 28, 2007
Posts: 804
Location: Ohio
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| Posted: Sun Jul 20, 2014 10:47 am Post subject: |
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| Why not a 4:37 8 bolt? unless you already have the 4:86, I have never broken a 4:37 but I have a 4:86. Is it just because of the gearing you need? I still believe a 4:86 in a swing axle is risky for longevity many people would say the same about a 4:37 but It probably depends on the make and quality of the 4:86 if your not hard on it. It being in a Baja and playing in the sand at all might shorten the life of it. You can always used close ratios with a stronger ratio R&P to get where you need unless first and second are too tall for you then go 4:86. Lots of options if you have flexability. |
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luvthemvws
Samba Member
Joined: February 13, 2012
Posts: 117
Location: Middle of nowhere
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| Posted: Mon Jul 21, 2014 4:11 am Post subject: |
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| I want to use the 4.86 because I got a good deal on the 4.86 and I want to keep the driveline as simple as practical. Thus no Bus trans or IRS conversion. As in any driveline, doing the gear reduction with the r&p takes a tremendous strain off the transmission and makes the driveline more efficient. |
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gears
Samba Member
Joined: October 28, 2002
Posts: 4391
Location: Tamarack, Bend, Kailua
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| Posted: Mon Jul 21, 2014 7:16 am Post subject: |
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The pinion may be some grade of 9310, but the ring gear would most certainly be 8620. IF the R&P is set up precisely, and IF the pinion is from an OK heat treatment batch, you should get reasonable service from a NEW Richmond 4.86.
You really should save up to install a REBUILT '75 Pyramid case bus box. JMO
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com |
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