Shaving SM420 fins for more driveline clearance (how much is safe) (1 Viewer)

[slickrock]

I need to open up a bit more room between my dana 18/SM420 for the front driveline. I could gain a little bit more if I do a small amount of grinding on the side of the SM420. Anyone know how much is enough to keep the strenth of the tranny's case?

 

[bsilva132]

you should be fine, the case is pretty thick. See Pinhead's tech write up for installing a 420, he cover's grinding the case:
sm420

 

[slickrock]

Thanks. I read that article. I have room at the pinon, but not a lot of room for a driveline. The stock set-up is for a 1.25" DL so I want to shave a little off the fins on the 420 that are a little farther forward than the output flange.

 

[bsilva132]

The earlier 420s did not have the fins and my understanding is that they were added for extra rigidity on the later cases. I would think you could grind down a lot of the fin and be fine.

 

[brooklyn]

Be Careful

If you research this you will see a few of us have punched a hole in the case. Not fun at all.

I ordered an adapter that slightly rotated "clocked" the bolts to give me more clearance. I didn't have to shave the "second case."

So go slow and make any other adjustment possible before grinding the case.

My old case didn't have fins the new one did.

Good luck.

 

[slickrock]

thanks for the response. Do you have any more information on the "clocking" ring you used?

 

[marks69cruiser]

Extreme bends sells the adapter your looking for.
Here is a link.SM420 Adapter : Extremebends.com | Landcruiser Toyota Parts and EBI 4x4 Accessories
I have a Extreme bends adapter and am very happy with it!!
Mark

 

[Poser]

thanks for the response. Do you have any more information on the "clocking" ring you used?

There is not a clocking ring for a Land Cruiser one piece transfer case, nor is there one for a Dana 18....

 

[G_Stratton]

I used this same setup SM420 adapted to a Dana18. The original U-joints off of the Dana18 were the small 1410 joints. I upgraded to the 1910 joints and ended up with a clearance problem where the piece holding the U-joint would tap the side of the transmission.

What I did to solve this was to grind down the parts of the U-joint piece till it cleared the side of the transmission. In my situation I didn’t have to take much off to clear. Once I did this I haven’t had any problems with it hitting the transmission.

 

[Poser]

The original U-joints off of the Dana18 were the small 1410 joints. I upgraded to the 1910 joints and ended up with a clearance problem where the piece holding the U-joint would tap the side of the transmission.

1310 perhaps?


Dana 18 did not have a 1410 yoke from the factory.


1910 joint?

Have any pictures of this setup?

 

[slickrock]

I ordered an adapter that slightly rotated "clocked" the bolts to give me more clearance. I didn't have to shave the "second case."



Good luck.

I was referring to the poster's statement.

 

[Poser]

thanks for the response. Do you have any more information on the "clocking" ring you used?

and I was refering to your comment...

Again,

There is not a clocking ring for a Land Cruiser one piece transfer case, nor is there one for a Dana 18....

 

[peesalot]

FWIW I have a non ribbed 420 with an orion using stock 70' fj40 flanges and a 1310 CV and I had to grind some on the tranny, some on the cv housing so when the driveline is completley horizontal the cv just clears the tranny case, by about 1/16". The driveline would never see that position as the stops limit axle befor it could. Just grind and check the drive line throughout it's cycle.

 

[G_Stratton]

1310 perhaps?


Dana 18 did not have a 1410 yoke from the factory.


1910 joint?

Have any pictures of this setup?

m

Could be - I remember going form a stupid small size to a joint that was comparable to stock Toyota size.

I'll get pictures this weekend.