Rising Sun Member Forums

Rising Sun Member Forums (http://www.risingsun4x4club.org/forum2/index.php)
-   General Tech Forum (http://www.risingsun4x4club.org/forum2/forumdisplay.php?f=17)
-   -   Gearing Woes (http://www.risingsun4x4club.org/forum2/showthread.php?t=11894)

Blackdiamond72 01-14-2010 04:10 PM

Gearing Woes
 
So I've never owned a 3sp 40 before and I'm finding my new one to be a real dog. 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.

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)?

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?

3. Quite a bit of people on mud swear by the sm420 or sm465, should I be looking that route?

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?

Any opinions would be great as I'd like to start collecting parts. Thanks!

James

LXBRADY 01-14-2010 04:16 PM

Quote:

Originally Posted by Blackdiamond72 (Post 133079)

3. Quite a bit of people on mud swear by the sm420 or sm465, should I be looking that route?

I have the sm420 in my 40. It acts like a 3 speed since 1st gear is 7:1 so it's useless on the street. I have 4:11's and 36 inch tires but instead of the 2F I have the 350F so I can't comment on the stock set up, but I am sure someone here will.

Blackdiamond72 01-14-2010 04:24 PM

What I found depressing is I called Merl at Classic Cruisers and he told me to put in a LS1. When I informed him that wasn't an option, he said to beef up my motor the best I can. Hmm

corsair23 01-14-2010 05:34 PM

I have a stock 2F in my 40, with stock gearing I believe (did the spin test and math came out around 4.11 :hill:), and a SM420

I'll ditto what Steve says about 1st gear in the SM420 and it being useless on the street...I think at max rpm I'm going maybe 10mph max.

My thoughts after owning a '76 with the stock 4spd and now the '74 with the SM420. The stock 4spd was a MUCH better street transmission. The gap between 1st and 2nd in the SM420 is huge and for all pratical purposes you have to start out in 2nd gear with the SM420 which puts additional wear/stress on the clutch IMO. That was the main reason I dropped down from 35s to 33s on my 40 shortly after buying it. With 35s, starting out in 2nd gear, you could just tell the clutch was crying in pain.

After all the great things I had read about the SM420 and SM465 I thought I really wanted one in my 40 and when I found a 40 with one in it that was a selling point to me. Now...well I love the SM420 for offroad crawling/control but 99% of the time I dislike the SM420 for its street manners. It is loud, clunky, shifts poorly etc.

I think if I had my choice and $$ were no object I would go with the Toyota 5spd (H55?), change the gearing in my diffs (4.56 if avail, not sure, or 4.88s) and see how I like it. If offroad capability takes a hit then I'd look into different t-case gearing or adding an Atlas or something.

At one time I thought I really wanted an NV4500 5spd but from what I hear there are downfalls with that tranny as well...

You're not exactly next door but if you ever want to come down and take the 40 for a spin to see what you think just let me know :thumb:

nuclearlemon 01-14-2010 05:54 PM

yes, you've got the 4.11 gears, and i wouldn't bother with an sm420/465. i had them and they aren't great. they are geared a bit lower for better crawlability, but they are a clunky truck tranny. swap in a cruiser 4spd and cam your motor. also send your carb to someone like jim c...he can do wonders. adjust your valves and give it a great tuneup, then remember you're not driving a sports car

LXBRADY 01-14-2010 05:57 PM

Quote:

Originally Posted by nuclearlemon (Post 133098)
and i wouldn't bother with an sm420/465. i had them and they aren't great. they are geared a bit lower for better crawlability, but they are a clunky truck tranny.

Hey, hey now I resemble that comment!

Air Randy 01-14-2010 08:49 PM

I have the H41 4 speed in my 40. It is a MUCH better option than an SM420. It has a 5-1 first gear versus stock H42 3.5-1 1st gear so you get lower gearing for off road but still very driveable on the street. Plus being it's a stock Toyota tranny it bolts straight in with no adaptors and will shift exactly like your H42. The only drawback is you usually have to pay about $600 for one in good shape. You can get them from MAF and Mark's Offroad plus several other places.

2nd and 3rd gear are also slightly lower ratios than the same gears in an H42 and 3rd is a nice split between 2nd & 4th. I think if your 2F is running good and with the H41 you would be real happy.

The aussies got the H41 so they could drive the outback roads in high range but their first gear was low enough to get them through a rough stream crossing or something similar without shifting into low range.

wesintl 01-14-2010 09:11 PM

problem is the gap between 2'nd and 3rd with a 3 speed. The 4 speed will allow you to 1.4 3rd vs 1.7 2'd 3 speed. Is it flogged in 2'nd at 30? Course the 33's don't help uphill.

If you did any changes I think the best bang for the $ is a h42

Blackdiamond72 01-14-2010 09:47 PM

I was leaning towards the h42 to begin with as they are cheap, plentiful and proven. I just figured why not ask to see what others thought on the subject. Correct me if I'm wrong, but all you need to do a 4sp conversion is the h42 bellhousing, new drivelines, and a adaptor for the 10 spline output. I figured I might as well get the 4sp transfer with the tranny to simplify things.

I would eventually like to go to 35s, so maybe changing the 3rds to 4.88 would be in order as well down the road.

Thanks corsair for the offer, I might have to take you up on that to confirm my feeling about the sm420. Are you going on Saturday?

corsair23 01-14-2010 10:10 PM

Quote:

Originally Posted by Blackdiamond72 (Post 133140)
Thanks corsair for the offer, I might have to take you up on that to confirm my feeling about the sm420. Are you going on Saturday?

Unfortunately I'm not going Saturday :( - Although taking the 40 on the snow run does sound fun :) - offer stands though if you ever find yourself down this way.


All times are GMT -6. The time now is 09:09 PM.

Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.