Cruiserdrew said:
We'll all sound like a bunch of echos here but:
The non-syncro first gear is a non-issue
The SM420 shifts fine and is strong as h*ll
The drive line mods are minor, but necessary (lengthen rear, shorten front drive shaft)
3rd and 4th ratios are a little too far apart on the SM420-not sure about the 465
Match the gear in your diffs to your tires-I run 4.56 and 35s, works well
60:1 or more crawl ratio is what you need for technically challenging trails
SM420 is a pretty simple swap but you need a 3 speed transfer case
I agree-rebuild the tranny prior to install in your Cruiser
The SM420 is noisier than the SM465 by just a bit
I did an SM420 swap a few days before CM04. (actually, I was grinding on the tranny reverse hump and put the front drive shaft back on the morning I left for CM04). Basically CM04 was my shakedown run for my SM420.....
I used one of Mike Smythe's plate adapters, and my 4 speed transfer case with a transition gear that Kurt with Cruiser Outfitters got for me. The 4 speed t-case is stronger than the 3 speed t-case. Slight gearing difference, however I don't think it's an issue.
I am running a 2F so I used a 3 speed bellhousing, and an index ring on the front bearing retainer. I also epoxied the TO bearing sleeve to the bearing retainer. I had to do NO drive shaft mods other than changind my '4 speed' slip yoke to a '3 speed' slip yoke, I had to make NO skid plate mods, and I had to do little custom fabrication.
I ran Poison Spider Mesa with the stock tranny at the CM04 pre-run and I ran PSM at CM04 with the SM420. NIGHT AND DAY difference on the trail. I am so sore at myself for not doing it sooner!
I originally used a junkyard SM420 that was shot. IT was jumping out of 3rd and 4th gear, and awas making some werid noises when I was driving down to CM04. I got a NEW Gamma Goat SM420 from a supplier in california. This tranny shifts just as smoothly as the stock 4 speed, and it isn't noisey at all.
Now for the things I don't like about the SM420.
1. I home brewed the transfer case shifter, and I have some problems with it clearing the tranny hump, so I disconnected the low range portion. It doesn't bother me that much so I really haven't bothered with it. The shift fork for the front drive engagement doesn't really work that well. AGain, this is partially due to my own design errors (originally I was going to do a twin stick, but I didn't have a good enough welder)
2. the gear spread from 3rd to 4th is a little too wide for the 2F with 4.11's in the diffs and 35'" tires. On the flats this isn't very noticable, but I do notice it going uphill. This is curable with 4.56's or 4.88's in the diffs.
Currently, I have a spare 4 speed t-case and a bucket with a 3 speed t-case gearset in it. I am debting rebuilding this case, and putting the 3 speed gearset in it. AT the same time, I plan on making a few t-case saver type devices and a stronger skid plate.
I am also debatign between going to 4.56 diff gears of 4.88 diff gears.
Anyhow, my 1/50th of a dollar.
HAve fun!
