Project Putt Putt: 2002 B3000 4x4 swap thread

[Dave18]

Haha oh yeah... Thank God rust isn't a big issue here. I feel like any wrenching project in Colorado sounds like "cheating" compared to what you guys have to deal with...

 

[Dave18]

Well it's been a while, partly because I got distracted by replacing the leaf springs, which I thought would be way easier than it was... I bought the springs, but realized there was some rust on the shackles so I decided to order new ones of those too. Then when it was finally time to replace them, the bolts had rust-siezed to the bushing sleeves. Ugh. I had to grind away a part of the bushing/spring and cut the bolt head off in order to get the old springs out.

Getting back on topic, I did reassemble the front differential! I used a dremel to open up the inside diameter of the pinion head bearing so it could be used as a trial bearing (since it gets pressed on over the pinion shim). I used the original shims on both the pinion and carrier, which I had read was a good place to start. I used the old pinion nut and torqued it to preload the pinion bearings for the trial assembly... this involved using one of those gauge-type torque wrenches to check the rotating resistance on the pinion, and torquing the nut until that resistance was in spec. The kit said to omit the crush sleeve for this stage, since it's one-time use. I'm not really sure whether pinion preload matters for checking backlash and pattern, but I figured I'd do it anyway just in case and for practice!
Then I lifted the carrier into place and torqued the carrier bearing caps. When I checked the backlash it was right in the center of the tolerance range!! I was consistently seeing .008" and the range is .006"-.010".

I went ahead and checked the pattern with the gear marking compound that came with the kit, and I thought it looked pretty good too, if a little bit high. The drive side looked especially good, and the coast side was offset towards the outside diameter of the gear.

I was very happy that it looked as good as it did, just using the original shims. I guess the gearset is the same, so maybe that helps. The Torsen carrier must be machined to be pretty close to the original open carrier, too!
Anyway next I took it all back apart to swap the trial bearing out for the actual new pinion head bearing. I had to stack a bunch of old races and large sockets to male a "press tool" deep enough to seat the bearing, but that went pretty smoothly. Then I re-installed the pinion into the housing, this time with a fresh crush sleeve and nut. I must have checked the pinion assembly a dozen times to make sure the shim, bearings, crush sleeve, oil slinger, and seal were all in the correct order! Once it was installed in the housing with the new crush sleeve, reaching the correct preload was a huge pain. I bolted a flange wrench to the u-joing flange and used my biggest wrench on the nut. Rather than holding the flange wrench with a breaker bar, I clamped it to my vise to keep the pinion from rotating. Get the biggest wrench imaginable for this step, haha! Or maybe I just need to exercise more. It was a PITA though.
Once that was done I reinstalled the carrier, torqued the bearing caps again, and re-checked the backlash and pattern. Mercifully, they still looked good!

 

[Dave18]

Well I've hit a pretty big snag - I did a test fit of the new diff under the truck, and it was clear that the front driveshaft will interfere with the y-pipe. I didn't realize it beforehand, but apparently the pipe is routed slightly differently on 4x4 trucks than on the 2wd. It must be specific to this year or Mazda too, because I don't remember it being mentioned on other conversion threads! Just looking at it without the front diff in place, it was hard to tell things wouldn't fit. There is some space between the y-pipe and the transmission, but not enough for the driveshaft.

Sadly, the OEM 4x4 y-pipe is no longer available from Ford, and it seems like nobody makes one in the aftermarket world, either! I see several manufacturers make the version that has catalytic converters integrated to the y-pipe, but my exhaust uses a single larger cat further downstream. Does anybody know where I could get a y-pipe that clears the front driveshaft? Is that the kind of thing an exhaust shop could fabricate?
I'm assuming using the version with two smaller cats in addition to my existing cat would result in too much backpressure, or deposits building up or similar.

 

[Lefty]

Well I've hit a pretty big snag - I did a test fit of the new diff under the truck, and it was clear that the front driveshaft will interfere with the y-pipe. I didn't realize it beforehand, but apparently the pipe is routed slightly differently on 4x4 trucks than on the 2wd. It must be specific to this year or Mazda too, because I don't remember it being mentioned on other conversion threads! Just looking at it without the front diff in place, it was hard to tell things wouldn't fit. There is some space between the y-pipe and the transmission, but not enough for the driveshaft.

Sadly, the OEM 4x4 y-pipe is no longer available from Ford, and it seems like nobody makes one in the aftermarket world, either! I see several manufacturers make the version that has catalytic converters integrated to the y-pipe, but my exhaust uses a single larger cat further downstream. Does anybody know where I could get a y-pipe that clears the front driveshaft? Is that the kind of thing an exhaust shop could fabricate?
I'm assuming using the version with two smaller cats in addition to my existing cat would result in too much backpressure, or deposits building up or similar.

 

[Lefty]

A good exhaust shop can take care of this for you. Years ago I had a 2.8 ford in an MGB. A shop installed dual exhausts with turn outs, easy peasy. Another shop recently put dual exhausts on my Ranger. They did a very nice job for a very good price.

 

[Dave18]

A good exhaust shop can take care of this for you. Years ago I had a 2.8 ford in an MGB. A shop installed dual exhausts with turn outs, easy peasy. Another shop recently put dual exhausts on my Ranger. They did a very nice job for a very good price.

Oh wow, you think so? I guess something like a simple y-pipe would be on the easier side for a shop that can do all that... I just have no experience with exhaust work, so I wasn't sure where the line was. I'll have to look for a good one somewhere nearby!

 

[Lefty]

Oh wow, you think so? I guess something like a simple y-pipe would be on the easier side for a shop that can do all that... I just have no experience with exhaust work, so I wasn't sure where the line was. I'll have to look for a good one somewhere nearby!

Go ahead. Get an estimate at least.

 

[Dave18]

Well it just happens that a fab shop that specializes in crawlers just opened about a mile down the road from me! I talked to the owner and he was thinking it might be possible to route the left side of the y-pipe around the driveshaft without touching the cats... it would be great if we could do that since Colorado has the same California rules about aftermarket cats and all that.

Does anybody with a V6 and 4x4 happen to know whether the y-pipe routes inboard or outboard of the front driveshaft? Routing it inside looks tough since there would be very little celearance to the transmission, but I'm wondering if it would be rock bait if you went all the way around the outside of the driveshaft...

 

[Dave18]

Here's a picture of what I mean... I put the camera on the transfer case output flange, so this would be looking right down the driveshaft if it were there. It looks like that exhaust pipe could route either way, but it would need to cut inboard pretty hard right dowstream of that mini-cat in order to clear the shaft. Going out and around seems a little easier to my untrained eye... (ignore the pinion flange wrench I left bolted on haha)

 

[Dave18]

Okay, large progress has been made. I had a shop reroute the y-pipe so it fits between the transmission and driveshaft... They had to actually take about an inch of pipe out above the first cat, so the cat would sit slightly higher and allow room for the pipe to smoothly curve away from the driveshaft:

They also welded on a bracket I had made to secure that 3rd differential mount point! Then, last night I began replacing the front suspension components. I've got the left side just about done, and am hoping to finish the right side tonight! New parts that are 4x4-specific are:

-4x4 Steering knuckle
-4x4 hub/bearing/ABS sensor assembly
-new CV axle
-4x4 brake rotor

I also replaced the following since they were somewhat old anyway. These should be the same between the 4x4 and 2x4 suspension:

-lower ball joint
-upper control arm w/integral ball joint
-tierod end

Removing the old steering knuckle (wheel spindle?)

New upper control arm:

The lower ball joint was a huge pain to remove and replace. The joint didn't want to separate from the spindle, even with a pickle fork and hammering on the spindle near where it presses in. I eventually drove the pickle fork in all the way and heated the bottom of the spindle with a small torch to hopefully expand the hole slightly... that worked eventually. Then, I had to whale on the top of the ball joint itself with a hammer to get it out of the lower control arm. Here's the new one getting pressed in:

Then I used a transmission jack to lift the differential into place, and installed the 4x4 knuckle with its CV axle! Bolting that on was a lot easier than I expected:

Look at those satisfying new M12 hub mounting bolts:

Now I just need to do it all again on the other side, and install my new steering rack. I am waiting on new bushings for that, since I damaged the old ones trying to get the dang thing removed from the frame crossmember. What a pain that was!
Oh yeah, and install the new stiffer torsion springs. And then get the whole thing aligned. So there is a lot left to do!

 

[Dave18]

Okay I got the other side built up last night and am pretty happy with how it looks!

A couple mysteries have emerged, which I hadn't thought about until getting everything bolted up where I can look at it:

1) The end of the CV axles are threaded... is there supposed to be an axle nut that threads onto these? It doesn't show up on the Tasca parts diagrams so I didn't order it. I can't figure out what that nut would do... the CV shaft is captive between the wheel bearing/knuckle and the differential housing, and there's no way it could fall out unless one of the ball joints were removed. It also shouldn't be taking any cornering loads, like the rear axle half-shafts do. Does anyone know where I can get this nut? This was the closest I could find online:

Advance Auto Parts - Down for Maintenance

2) I don't understand how wheel camber is adjusted on the Mazda B Series... Maybe it's different than the Ranger? I assumed there would be a cam-like flanged bolt/nut on the upper control arm pivot, which a shop would clock in order to move the arm in or out slightly... that's what shows up on Ford's part diagrams at least.

However, mine has a small plate with a hole in it to locate the UCA pivot bolt on the nut side. The plate wedges between two tabs on the frame mount and doesn't appear to be adjustable. Is this something a shop did at some point? Could I replace the plate with the cam bolt if I ordered it? I didn't bother buying the cam since I figured there must have been some way the truck had been aligned before - I assumed it would already be in there!

 

[Dave18]

Also I just realized the nut does show up as Item 3 on that parts diagram I posted... it just isn't listed for sale by Ford (or not on that page at least...) Hmm.

 

[Uncle Gump]

The axle nut keeps the hub on the axle. Without it the hub (wheel flange) will walk out of the bearings and the loose their preload.

I could be wrong... but it appears you don't have the eccentric washers that adjust camber.

 

[Dave18]

Oh interesting... so the hub/bearing assemby sort of needs to be squeezed between the axle nut and the end of the outer CV joint section of the axle? I guess that makes sense now that I think about it... It's hard to picture what that sealed hub assemby looks like inside! That would imply that you can't use the truck without the CVs installed too. Which I guess doesn't really matter since they are also needed to seal the front diff.

I ordered the nuts from Advance.... hopefully they are the right size and get here soon! I'm sort of bummed Ford didn't include them with the CV axles I paid top dollar for haha.

You're right about the missing eccentric washers. What I'm confused about is how the truck was ever aligned in the first place! I've been driving it for years without any uneven tire wear... Maybe I just got lucky and all the tolerances stacked in my favor?

 

[Uncle Gump]

I would have expected those nuts to have come on the axles too... since they are recommended one time use. But... times have changed... why not sell them to you separately.

The camber washers??? If it was aligned and locked down... you could drive forever as long as they didn't move. Weird though... never seen a truck without them.