Thread: Gearing Woes
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Old 01-15-2010, 10:16 PM
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Rzeppa Rzeppa is offline
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Join Date: Aug 2005
Location: Kittredge CO, USA
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Quote:
Originally Posted by Blackdiamond72 View Post
So I've never owned a 3sp 40 before and I'm finding my new one to be a real dog.
I drove my 71 on and off road for many years before I swapped an H42 into it. I loved the 3 on the tree but the 1st ratio was interesting off road and made me a better driver. As far as engine performance, carb and ignition timing are the real keys to get up and go. The old F is actually pretty peppy when set up right. 2X on the 2F.

Quote:
Originally Posted by Blackdiamond72 View Post
Its on 33"s with a 2f and original driveline behind it. Going up hill near my house in high is near impossible above 30mph. My 78 wasn't a champ either but it did much better than the 69.
Again, carb and ignition timing are really key.

Quote:
Originally Posted by Blackdiamond72 View Post
My questions are:

1. Does the 69 have 4.11's in the diffs? Is it worth it to go to 4.88's (cost vs performance)?
In order, yes, and no

Quote:
Originally Posted by Blackdiamond72 View Post
2. I'm planning on going to a h41 4sp later this year, I know that 4th is still 1:1 so no improvement there but will 3rd be close to a split between 2nd and 3rd in a 3sp tranny?
I have an H41 in my 76 and had an H55F in my HZJ75 with pretty much same ratios. WAY better than SM420/SM465/NV4500 as far as shifting smoothness, and as others have mentioned, the SMs are basically 3 speeds for everything but off road, 1st is granny gear and you really don't want to start out in it on road. The H55F and NV4500 are too long for a 40 because your rear DS becomes way too short unless you're lifted like crazy and you've built a buggy IMHO.

Quote:
Originally Posted by Blackdiamond72 View Post
3. Quite a bit of people on mud swear by the sm420 or sm465, should I be looking that route?
See above

Quote:
Originally Posted by Blackdiamond72 View Post
4. Also, I know that the gearing in the 3sp transfer is lower than the 4sp transfer in low range, worth swapping the gearing from the 3 to 4sp case?
Yes

When I swapped my H42 into my 71 using my 3 speed t-case I ran into a bunch of gotchas that you won't see on mud, but I wrote them up here.

Happy cruisin'!
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Jeff Zepp
Kittredge CO USA
1971 & 1976 FJ40s, 1978 FJ45, 1987 FJ60
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