LS Swapping the Mini Truck (LQ9)

[dan1554]

I FINALLY have 4wd.

Yeah the angles are nasty. Tom Woods sent me a driveshaft with offset u-joints that should handle it. The only problem is that past 30mph or so it gets an expected vibration because the u-joints cause the drive shaft to wobble. There really wasn't any way to correct this short of cutting apart the front axle and changing the transfer case position. The TW rep said its a problem with nearly all mini SAS setups. My only concern here is getting to/from trails in icy conditions. I don't want a trailer rig.

Also, if I go over any sort of large ledge or rock, it could contact the DS. Something Ill have to live with for now, but might look at armor options later on.

I also came out one day to find my scangauge was inoperable. Found the problem. Im attributing it to my smearing dielectric grease on the connector. Probably obvious to everyone but me that this is neither necessary or an appropriate use. The more you know! Re-pinned, cleaned and back in service.

Next rare bit of free time I get, I'll triple-bleed the brakes. I think there is still some air from when I did the SAS. Between the 35s and the 6 liter, they need all the help they can get. In low range, you need to shift to neutral or forget about stopping. So close to being back on a trail!

 

[dan1554]

Another stupid mistake, when I added shims, I was working to get the axle back to factory spec. This meant I was reducing caster, when it needed all the caster it could get. So I flipped them around. I also replaced the bad shock. Death wobble fixed!

 

[Hulk]

Tom Woods didn't recommend a double cardan drive shaft? I thought that was the ticket for higher angle situations.

 

[dan1554]

Tom Woods didn't recommend a double cardan drive shaft? I thought that was the ticket for higher angle situations.

I have the DC shaft they made me the first time around waiting to go to town for a return. I tried it (luckily on a vehicle lift) and it fell apart at full droop. Also, reversing the shims did nothing good for the angle at the 3rd member. I could probably run a DC shaft on the street, but once I got in to a full droop or crossed up situation its survival would be questionable. Paraphrasing TW here. Here's an article about it:

Toyota Front Drive Shaft for Solid Axle

The front shaft in Toyotas with solid axle swaps (SAS) or highly flexible leaf springs can get a bit complicated. These types of suspension setups in Toyotas create a couple of problems, problems with angles and with compression/extension. The compression/extension issue is why you’ll see guys...

4xshaft.com

 

[Hulk]

Ah, interesting stuff. You've probably thought this to death at this point.

 

[J Kimmel]

No one wants to hear it but cut and turn those knuckles. You can get your shaft up out of the rocks have no vibration at speed and good caster.
I can tell you I always thought full hydraulic was always just twitchy, nature of the beast so to speak but building new 609’s last winter with correct caster I never experienced it so smooth.

Food for thought

 

[dan1554]

@Hulk Yeah you would think... Some things, like the shims and exhaust routing, make me wonder where my brain was.

@J Kimmel Good ideas; the next iteration will probably have me doing something with the front axle to correct the angles. Might be a good thing to do in combo with a future atlas TC and future shop space. My concern about rotating the knuckles is that the steering components are probably going to be in the way. Also I just want to get out and wheel. I won't be doing KOH any time soon.

Or just go 'won ton' and fix it all then.

 

[DanS]

@Hulk Yeah you would think... Some things, like the shims and exhaust routing, make me wonder where my brain was.

@J Kimmel Good ideas; the next iteration will probably have me doing something with the front axle to correct the angles. Might be a good thing to do in combo with a future atlas TC and future shop space. My concern about rotating the knuckles is that the steering components are probably going to be in the way. Also I just want to get out and wheel. I won't be doing KOH any time soon.

Or just go 'won ton' and fix it all then.

Need a spare '85 axle housing to do the cut and turn at your leisure? I think I've got three.

Dan

 

[dan1554]

@DanS I'd love to take you up on that offer! Let me know what I can do for you in return. This won't happen until after the icf-mahal is built.

 

[DanS]

@DanS I'd love to take you up on that offer! Let me know what I can do for you in return. This won't happen until after the icf-mahal is built.

Excellent! I'll try to remember next time I'm coming up from NM to toss one in the truck to drop it off for you.

Dan

 

[dan1554]

@DanS That'd be great! Good to have you visit as well.

Regarding the brakes, there's about a 6psi drop from manifold pressure with engine off vs on. Im not sure if this is the correct way to read vacuum, but that comes out to ~12 in hg which is low. Someone please tell me if Im off track in my logic. So next chunk of free time I get, Ill be looking for vacuum leaks.

 

[rover67]

@DanS That'd be great! Good to have you visit as well.

Regarding the brakes, there's about a 6psi drop from manifold pressure with engine off vs on. Im not sure if this is the correct way to read vacuum, but that comes out to ~12 in hg which is low. Someone please tell me if Im off track in my logic. So next chunk of free time I get, Ill be looking for vacuum leaks.

do yo uhave a good vacuum check valve on there for the booster?

 

[dan1554]

@rover67 Its on my list to check. I imagine I could just blow through it to test?
Also my problems are mostly near idle. After I get moving its not so bad. But low range on a slow trail could be scary. In my dirt drive, the rear wheels dig with the brake pedal to the floor.

I also remember the brakes being not so great with the 4.3.

Some other thoughts Ive had is a vacuum reservoir and/or an electric vacuum pump. But I think those could be masking the real problem.

Also a note for myself to check: LSPV. I think the arm angle changed after the lift: https://forum.ih8mud.com/threads/lspv-optimal-height.938225/

 

[dan1554]

Well I fixed my brakes. Un-bolted the LSPV arm and tied it up to the frame with baling wire Immediate and dramatic improvement. Can't believe I lived with poor braking for all this time when the fix was so simple. Will find a better way to permanently affix the arm, and maybe do a bypass of the LSPV in the future.

I had it sitting for a while and someone moved in and chewed up some wires. Worst was an injector circuit. So I spent a bit of time splicing new wires in to my harness

And I finally got it out on the trail. Its fine until you start doing slow climbs, then the temperatures creep up. My understanding is that normal operating temps are around 210-220F for these engines. At 235 I had to pull over and let it cool. This happened a couple of times.

Im going to try pusher fans but not getting my hopes up. Pessimist in me thinks itll require hacking up more of the front, maybe creating custom radiator bracketry, and trying to go bigger with the rad and fans. Add that to cutting and turning the front axle and Ive got work for years to come.

On a positive note, nothing got bound up or made contact with the front axle/driveshaft. This is the first time its been on the trail since I did that work too. The ride is also noticeably better. Its nice going over swales at speed and not getting a steering wheel to the teeth.

 

[satchel]

In case this hasn't already been discussed here, try bypassing the coolant lines. That helped my truck a lot. If you aren't aware, these engines want to have coolant flowing through the heater core always and yours likely is not allowing for that so it may be creating a coolant blockage.

 

[dan1554]

@satchel that'll be what I try next, thanks!

 

[dan1554]

Started chipping away again. I had a neighbor's 60 that I was rebuilding so the mini took a major backseat. I was still getting unsettling swaying at 60+ mph especially when going around corners with the engine loaded. Put anything in the bed and it became much worse. Strong crosswinds were also a problem. Got some time to install a tk1 universal sway bar.

I can get little wobbles in high speed sustained corners but its so manageable I dont feel the need to back off at all. Best of all its way more fun to drive now that I know I can open it up on the highway safely. Still need to test it with loads and on the trail. My understanding is that it should keep the truck flatter and cause the front suspension to flex more. I was getting sketchy lean on off-camber so Im guessing this will make a world of difference there too.



Cooling is still a problem. I put pusher fans on it, and that helped. Now instead of having to pull over and turn the engine off, I can pull over and have the temps decrease with it running.

Ordered a new 2-row 3-inch thick radiator. I have a 3-row 1.5 inch thick in it now. Hoping the doubled core thickness will help. More surface area and more volume can't hurt, but Ill have to cut more of the stock radiator supports and body bracing out of the way and reinforce whats left.

 

[Notyourmomslx450]

Started chipping away again. I had a neighbor's 60 that I was rebuilding so the mini took a major backseat. I was still getting unsettling swaying at 60+ mph especially when going around corners with the engine loaded. Put anything in the bed and it became much worse. Strong crosswinds were also a problem. Got some time to install a tk1 universal sway bar.

I can get little wobbles in high speed sustained corners but its so manageable I dont feel the need to back off at all. Best of all its way more fun to drive now that I know I can open it up on the highway safely. Still need to test it with loads and on the trail. My understanding is that it should keep the truck flatter and cause the front suspension to flex more. I was getting sketchy lean on off-camber so Im guessing this will make a world of difference there too.



Cooling is still a problem. I put pusher fans on it, and that helped. Now instead of having to pull over and turn the engine off, I can pull over and have the temps decrease with it running.

Ordered a new 2-row 3-inch thick radiator. I have a 3-row 1.5 inch thick in it now. Hoping the doubled core thickness will help. More surface area and more volume can't hurt, but Ill have to cut more of the stock radiator supports and body bracing out of the way and reinforce whats left.

what temps are you seeing??
LS motors run hot on the normal.
they like to run 210, 215 it makes me crazy how hot they run.
i'm usually around 200 with electric dual speed fans and a 180 t-stat

 

[dan1554]

It edges toward 230 before I pull over. I really think the rad I have is too anemic. Its also a mild cammed 6 liter tuned for premium fuel. A de-tune to 85/87 octane is probably in order for heat, cost and fuel availability.

 

[Notyourmomslx450]

is it in front of the motor or in the bed? i have a 4 core alum rad and i added hood louvers to help keep the heat down