2008 v8 tow build

[Dave_in_VA]

I'm planning a Virginia to Anchorage and back road trip, likely in 2026 or 2027, after I retire. Just my wife, dog and me.

I've got a 2008, v8 with currently 142k miles. Extensive maintenance and upgrades have been done, including:
* full frontend rebuild, 5100 shocks, Camburg UCAs
* 4.10 gears with LSD
* 275/60r20 Terraincontact tires wheels
* frame sandblasting and painted
* 5th gen brakes
* 7 pin Redarc electronic brake controller
* CSF HD radiator
* y-pipe and full exhaust
* lots of interior and LED light mods
* lots and lots of drive train maintenance
* Front end modernization
* New leather interior, stereo, sound dealing, etc.

Working on the 4runner is my hobby

I'm still researching trailers, but plan is one about 22-24' total length, 550ish tongue weight, and <6k total fully loaded weight.

Planned future mods before the big trip include:

* Nomad HD transmission valve body upgrade
* Nomad electronic torque converter lockup kit
* oversize trans cooler
* Stoptech 6 piston front and 4 piston rear big brake kit
* 4.88 differentials
* HD / taller rear springs, likely also SummoSpring bump stops (to keep headlights properly aligned and keep rear with a level to slightly up rake)

The gears and Nomad parts should significantly help performance. The TC lockup kit allows me to manually lock the torque converter in 2nd to 5th gears. This keeps trans temps low. The HD valve body improves fluid pressure, allows for more engine braking, pushes more fluid to cooler, etc. This trip has some big hiils and I'm sure I can use all the power available in the small 4.7 v8.

My target towing speed is 60ish in the 2200 or so RPM range when on flat ground. On hills, 3rd to 4th gear in 3k or so RPM, depending on hill incline.

Below is a gear mapping to speed calculations with the 4.88 gears.

My question, will this build comfortably tow on this trip.

 

[Dave_in_VA]

Here is a vehicle picture

 

[Runnin on E]

Wow those are a lot of mods. One I don't see is the larger 8.2 rear diff. I got mine out of a 2012 FJ plus bonus rear elocker....I didn't just swap for the locker but specifically to tow.

 

[alia176]

Hey Dave,

Congrats on the upcoming retirement fella!! I applaud your attention to details, and I think your rig may not like towing the length and the weight of your trailer over that distance. My concern is for the safety of you and other motorists around you. This trip is going to be massive and my *assumption* is that you're going with a hard sided trailer. Your tow rig is dinky, for lack of a better word. That's a lot of hwy with lots of cross wind that will absolutely tire/stress you out with a 4runner. You'll be a very active driver with that trailer, and sway control could possibly exhaust you.

Just for reference, I have a dinky Australian popup with a 400# tongue weight, and a wet weight of 2600#s. My V8 tows it with ease due to the very little air drag, so I'm trying to imagine a heavier trailer with a large form factor. I have Air Lift 1000 air bags inside the rear coils for the times I'm towing this trailer. I assumed a large form factor due to the 500# tongue weight you're envisioning.

Again, congrats on the big life change and the awesome trip that's upcoming.

 

[Runnin on E]

Dave in VA hey we're can I find that gear mapping app? That one looks good.

 

[Dave_in_VA]

I'll upload the spreadsheet next time I'm on my computer.

 

[rdruss]

Hope you chose a quiet exhaust, it's going to be barking at you.

 

[Dave_in_VA]

Hope you chose a quiet exhaust, it's going to be barking at you.

I did go quiet.

The y-pipe is from Doug Thorley, no secondary cats, but there's a resonator immediately after each exhaust connection.

Removing the secondary cats increased drone significantly.

The 4runner now has a nice mellow sound. Definitely louder than stock, but ZERO drone.

I went through approximately 20 muffler combos before I was happy. During this process I was worried that Amazon would stop accepting my returned mufflers

Immediately after the y-pipe, I have a Stainless Works turbo muffler, this is the only muffler with a chambered.

Next a short pipe and hanger, which is bolted to a cross member above.

Then I have a Magnaflow 5x8x24 inch muffler.

The over the axle pipe is Gibson. The post y-pipe exhaust started out as a Gibson kit. But that solution droned way to much, gave me headaches.

Then I have a 4x14 inch Borla resonator which has a 4" exhaust tip welded at the end.

All exhaust is stainless 2.5 inch.

 

[Dave_in_VA]

Wow those are a lot of mods. One I don't see is the larger 8.2 rear diff. I got mine out of a 2012 FJ plus bonus rear elocker....I didn't just swap for the locker but specifically to tow.

Too late for that as I'm $3k In gears now. I wasn't tracking that i could change out the rear axle.

What do you tow? Mods to your 4runner?

 

[Dave_in_VA]

Just one more thought, I could also go 5.29 gears, a little more RPMs, a little slower:

 

[Dave_in_VA]

Dave in VA hey we're can I find that gear mapping app? That one looks good.

Hi, please see attached. FYI, you will have to unzip the file before using as .xlsx files cannot be uploaded un-zipped.

 

[Runnin on E]

Too late for that as I'm $3k In gears now. I wasn't tracking that i could change out the rear axle.

What do you tow? Mods to your 4runner?

Thanks for the spread sheet.

I had to pull a Kubota 4740 tractor. 4200# without the backhoe plus my trailer weight put me at approx max capacity 5500-6000. It did it but it was SLOW going (stock gears) mostly 3 and 4th gear. But now I know where the limits are for towing, I would not tow that heavy again for any distance (about 150 miles to pick up the tractor). I also moved my tool box, I'm guessing it weighs 3500# (ya shes a fat one).
I have Dobinsons springs and shocks about 2.5" lift. Coastal Offroad bumpers front and back with dual swing out. 12K winch up front. RCI full length skids and rock sliders.
When I picked up my tractor I did not have the skids, bumpers, winch or sliders on yet, just the Dobby lift.

 

[rdruss]

You might want to consider an axle ratio where you would be happy in direct, rather than OD. I think when in OD it heats trans a little more than direct, OD not as efficient as direct, from my understanding.

 

[ArthurKotb]

You don't mention if the trailer is travel trailer or gear trailer. Tongue weight is the challenge because the 4WD maxes out at 700 lbs., which includes the hitch weight. Even that depends on if you have propane tanks and if they are filled. Batteries are also additional weight. You want 60% of the weight in front of the axle(s) and 40% behind or you'll have uncontrolled sway in an emergency situation.

I pull a 23' Airstream that maxes out at 6500 lbs. When I take it to storage it has the propane tanks mostly filled, has the kitchen stuff, blankets, gear for the campsite etc. Holding and fresh water tanks are empty. There is no food or water, clothing, TVs, miscellaneous comfort gear etc. The tongue weight is 730 lbs. at that point. I use an Equalizer WD hitch to offset the hitch weight when I add in the food, clothing and other gear.

I have traveled from KY to OR across the middle US route, returned across the north route and down through MN, IL, IN to KY. I have traveled to D.C. and down to FL and across to TX. My '04 handles very well but headwinds are a problem. With a strong headwind (at least with a travel trailer) I can go 60, 65 in a pinch. With no headwind or even a tailwind I travel at 70, except through the mountains. Then my speed will drop to 50-55. I get 9-13 MPG depending on the wind. On the trip out to OR it was a headwind both ways; not fun.

You don't say what your experience is with towing a large trailer. I've towed box trailers and boat trailers but the travel trailer was a big change. You want to get some miles under your belt if you've not towed anything that big.

 

[ArthurKotb]

You might want to consider an axle ratio where you would be happy in direct, rather than OD. I think when in OD it heats trans a little more than direct, OD not as efficient as direct, from my understanding.

I pull in OD most of the time, but that's downhill and flat land, no headwind. If it's an incline or headwind I drop to 4. I have a feel for the engine and I can tell when it's lugging. With any acceleration I move to 4 or even 3 going over hills.

Most of my travels are in cooler weather. In extreme heat I'd advise to stay in 4.

 

[Dave_in_VA]

You might want to consider an axle ratio where you would be happy in direct, rather than OD. I think when in OD it heats trans a little more than direct, OD not as efficient as direct, from my understanding.

I agree with your suggestion and have researched this issue.

In 5th/OD a stock TCM (trans control module) unlocks the torque converter a lot. In 4th, the stock TCM only occasionally unlocks the torque converter, its dependent on requested engine load, ie thottle position. Torque converter use fluid in the torque multiplication process, this significantly increases trans fluid temp. Heat is the evil enemy of any transmission.

The torque converter lockup kit I referenced is a piggyback unit to the TCM. It intercepts and can change the lockup status of the torque converter. It has a manual button that can electronically lock the torque converter, regardless of what the TCM is trying to tell the torque converter. This way I can run in 5th gear for hours (if desired) with a locked torque converter. This kit also allows shifting gears (2nd to 5th) with a locked converter.

As a note, the manufacturer has a model that also locks up 1st gear. This is used by hard core offroaders as an downhill engine brake. I didn't want this version as my offloading is very limited.

By choosing a high gear ratio, ie 4.88 or 5.29, with the torque converter lockup kit, I get full use of all 5 gears and can still keep the trans fluid temps in check.