Questions About My Samurai Mods

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Originally Posted by Billjohn

To install the Toyota CV's you will need a set of 'Rat Adapters'. These are adapters that will allow you to bolt them right in. Scott builds them at 4XFabrication.
https://www.rock4xfabrication.com/st...1e21f81c96603e
Look for Rat Adapters.

The shims can be used to improve the drive shaft angles, but in front - you will also change the caster angle of the knuckles. This will increase any vibration you have up front. Just don't go too big with the shims.

Hi Bill,

I didn't understand how is this going to help. Here's the Rat adapter from the above link:


This means I will have to change the whole drive shaft as well, right? Then what? The angle will still be the same, no?

Originally Posted by ack

Shims are the DEBIL!

While they can be used to correct any driveshaft angle problems relating to NON_OEM setups (like counteracting the effect on pinion angle changes in a shackle lift) they should NEVER be used to point the third member to "get a better operating angle" on the u-joints!

ALWAYS do whatever you have to do to keep the faces of the pinion flanges parallel to the faces of the transfer case output flanges as described in:

Driveline Basics with Steve Johnson - ORN

and

Tom Wood's Custom Drive Shafts - Driveline 101

The only exception is the use of a Double-Cardan driveshaft (Toyota 4x4 PU fronts with RatAdapters as Bill mentioned) also as described in the above links.

Following the above information will result in a smooth-operating driveline. Any other vibrations will be related to existing conditions like worn t-case mounts, worn input/output bearings or worn u-joints.

BTW: The above links should be REQUIRED READING for anyone who owns a lifted truck or is considering lifting a truck.

I hope that this helps!

I'll go through the two links thoroughly tonight and come back with more question.

Thanks guys for the great help. You didn't say what you think of my truck (compliment fishing)

[Billjohn]

Yes, it means changing the driveshaft.

A regular (two u-joint) driveshaft has a balance issue that has to be near perfect to limit vibrations. The u-joint at both ends must be at the same angle to offset the other. Any difference in those angles will cause increasing vibrations as the rpm's increase.

A CV joint (or double cardon joint) is like a U-joint on steroids... it will allow for more of a controlled angle while not requiring the opposite end of the driveshaft to match that angle. So if the angle at the t-case remains basically the same and the pinion side u-joint changes angle because of the suspension change, the CV joint will work without increasing vibrations.

I have an article on swapping to a much higher end CV driveshaft that shows a few pics you might want to see. The higher end isn't required for most upgrades, but I abuse the shafts on the rocks so I wanted something stronger.
CV Driveshaft

[ack]

Originally Posted by alternator

Hi Bill,

I didn't understand how is this going to help. Here's the Rat adapter from the above link:


This means I will have to change the whole drive shaft as well, right? Then what? The angle will still be the same, no?



I'll go through the two links thoroughly tonight and come back with more question.

Thanks guys for the great help. You didn't say what you think of my truck (compliment fishing)

Yup, you swap out the whole driveshaft! There is a data page at rock4xfabrications.com that lists all the different year Toyota 4x4 pickups that have front driveshafts that you can use. Some are literally bolt-on while others require a bit of cutting before installation. You can find them pretty cheap at salvage yards and pick-n-pulls. Rebuild kits are also easy on the wallet.

Here is an alternate link to that info:

Toy D-Shaft Information - Zukikrawlers

When I installed my Toyota DC driveshaft, I set my truck on level ground with a typical load onboard (weight equal to me and a full tank of gas) and my perches cut loose. I then rotated the pinion up until the angle on the differential end u-joint was zero. Then I welded (actually Smuz did it) the perches back in place. The result was a vibration-free rear driveshaft setup with plenty of flex. There is the possibility that the pinion bearing may not be getting it's normal flow of lubricant because of the new operating angle. I tried to fix this with a little more lube in the dif housing.

Your tintop is very clean! And Yellow (a color that I have scattered thoughout various places in the Ackmobile)! No nasty dents or rust spots!

I'm from the R&P camp so I cannot comment on the t-case gearing

I hope that this helps!

[alternator]

Originally Posted by Billjohn

Yes, it means changing the driveshaft.

A regular (two u-joint) driveshaft has a balance issue that has to be near perfect to limit vibrations. The u-joint at both ends must be at the same angle to offset the other. Any difference in those angles will cause increasing vibrations as the rpm's increase.

A CV joint (or double cardon joint) is like a U-joint on steroids... it will allow for more of a controlled angle while not requiring the opposite end of the driveshaft to match that angle. So if the angle at the t-case remains basically the same and the pinion side u-joint changes angle because of the suspension change, the CV joint will work without increasing vibrations.

I have an article on swapping to a much higher end CV driveshaft that shows a few pics you might want to see. The higher end isn't required for most upgrades, but I abuse the shafts on the rocks so I wanted something stronger.
CV Driveshaft

Thanks Bill, very clear explanation. So if I get the CV joint drive shaft then I can use shims to tilt the diff to get a 180 degree angle driveshaft (or zero degrees depending on where you measure it from )

Originally Posted by ack

Yup, you swap out the whole driveshaft! There is a data page at rock4xfabrications.com that lists all the different year Toyota 4x4 pickups that have front driveshafts that you can use. Some are literally bolt-on while others require a bit of cutting before installation. You can find them pretty cheap at salvage yards and pick-n-pulls. Rebuild kits are also easy on the wallet.

Here is an alternate link to that info:

Toy D-Shaft Information - Zukikrawlers

When I installed my Toyota DC driveshaft, I set my truck on level ground with a typical load onboard (weight equal to me and a full tank of gas) and my perches cut loose. I then rotated the pinion up until the angle on the differential end u-joint was zero. Then I welded (actually Smuz did it) the perches back in place. The result was a vibration-free rear driveshaft setup with plenty of flex. There is the possibility that the pinion bearing may not be getting it's normal flow of lubricant because of the new operating angle. I tried to fix this with a little more lube in the dif housing.

Your tintop is very clean! And Yellow (a color that I have scattered thoughout various places in the Ackmobile)! No nasty dents or rust spots!

I'm from the R&P camp so I cannot comment on the t-case gearing

I hope that this helps!

Ouch! Why didn't you just use shims, instead of removing and re-welding the perches? Your perches are the type that rest directly on axle, instead of on the OE perches, I guess. I heared this type ain't good, because the axle housing isn't strong enough to handle the abuse.

BTW, my tintop wasn't that clean or rust-free, I had that done. This is how it actually looked like when I first bought it, and it was VERY rusty and all dented up. It was owned by some local news paper company, used for distribution of papers. I think the transfer case was NEVER used. The transfer case lever handle felt like new, and looked like new, depsite the condition of the car. The transfer case gears looked completely wear-free, although the car had more than 200,000 miles on it.

IF I have stock axles and a stock case what shaft do I need.
OPTIMAL WAYS FOR THE REAR
1) You can get away with 79-85 CV in the rear May need to be shorten'd depending on the year shaft you get 84-85 is longer hen the 79-83.
2) 86-88 4cyl CV will work the v-6 is hit or miss depending on what Toyota had in stock
3) 89-95 4Runner rear NON-CV shafts cut down to length and have roughly 42 deg at the joints

OPTIMAL FOR THE FRONT
1) 89-95 4Runner rear NON-CV shafts cut down to length and have roughly 42 deg at the joints

What about HiLuxes? 80's 4Runner and HiLux are based on the same platform, I'm guessing they have the same drive shafts. Maybe a longer rear drive shaft for the HiLux due to the longer wheel base because of the truck bed.

[ack]

Originally Posted by alternator

Ouch! Why didn't you just use shims, instead of removing and re-welding the perches? Your perches are the type that rest directly on axle, instead of on the OE perches, I guess. I heared this type ain't good, because the axle housing isn't strong enough to handle the abuse.

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What about HiLuxes? 80's 4Runner and HiLux are based on the same platform, I'm guessing they have the same drive shafts. Maybe a longer rear drive shaft for the HiLux due to the longer wheel base because of the truck bed.

In my visits with literally hundreds of Zuk owners at various events, the vast majority of them with SPOA-lifted Samurais used welded perches as opposed to clamped "weldless" type - sold by Rocky Road - fitted with shims.

The logic:
Welded on perches - like the OEM units - are stonger. There is no possibility of postion-shifting as a result of depending on friction and presure to hold the perch in place. If the factory does it this way, why not use the same method with aftermarket perches? More objective evidence on this in a moment...

Shims - especially aluminum shims - can corrode and break. They also depend on friction, presure and the spring pin for positional stability. If the shim fails, bad things happen.

Welding onto the Samurai axle. Yes, if you are a total klutz with no formal knowledge of welding at all, you can totally mess up an axle tube or the perches by either overheating the weld or not heating them enough. My first major welding task - after a bit of self-training - was welding my perches. It was a complete success! Not bad for a television engineer...

Now the subjective stuff:
1. Hundreds of Samurai owners with welded perches can't be wrong!

B. Remember that "in a moment..." comment above? Diety forgive me for I have Sinned... The last Samurai that I parted out (yes it was driveable but just barely) had Rocky Road Bolt-on spring perches. This truck was set up as a Mudder and had been "rode hard and put away wet" many, many times in it's late career.

When I started to remove the axles, the flat pieces of steel in those Rocky Road Perches that were machined to cause the perches to rest exactly opposite from the OEM perches... were seriously distorted! The new perches were NO LONGER parallel to the old perches! This is certainly not a good thing, is it??

Thus my distain for any form of perch attachment other than welding.

About the types of Toyota Pickups: It is quite possible that 80's Hiluxes and 4Runners may use the same type of driveshaft. From your truck's "before" picture, I assume that you are not currently living in North Amreica. There is a possibility that North American Toyotas are equipped similarly to international versions. Unfortunately, the only real way to test this hypothesis is to measure the length of a Samurai rear driveshaft, then go to a salvage yard and measure the length of a HiLux/4Runner front dsriveshaft. If the local Toyota driveshaft is equal or slightly longer than the Samurai unit then you have the part that you need!

For a slightly less answer riddled with guesstimates, you could email your driveshaft question to Rock4xfabricationinc@comcast.net.

Part of the fun that is called "modding" is the occasional trip to the salvage yard with tools, notes and a tape measure.

I hope that this helps!

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I'm with you when it comes to welding perches. Mine are welded perches. What I meant is that you don't need to remove the welded perches and re-weld them, you could have used shims instead. Or so I thought. But thanks for the great info.

True, I'm not in North America. But the specifications of the Samurai here and there are identical.