Thoughts on Gen 1 4RUNNER - Chinook Swap

[4RUNNY]

Hi there,

Been awhile since my last post but I have found some new inspiration after a sensational weekend touring in a 1983 Toyota Dolphin RV.

After finding a beautiful 1978 Chinook cabin for sale here in town, I have become obsessed with the idea of turning my 1989 4runner into a pop top RV, with the classic Chinook swap, as seen here applied to a mini truck:

https://forum.ih8mud.com/expedition-builds/536963-custom-4x4-diesel-chinook.html

Does anybody see any forseeable problems with applying this swap onto a generation 1 4runner. If i remember correctly the body mounts are in completely different locations than the minitruck bed mounts, so I understand some mount adjustment and fabrication will be required. I figure I strip the 4runner down to the bare components and frame behind the cab, place the chinook cabin on the frame, and take measurements, design and install the mounting systems, and the hard part is finished. Any deal breakers or other reasons I should avoid this build??

Basically, I'm looking for the big differences between the minitruck and 4runner behind the cabin that will make this a challange before I dive in.

Thanks,

-Brian

 

[KLF]

The truck in your link was a longbed, so it will be a LWB frame. 4Runners use a SWB frame, the difference is ~9-1/4".

 

[meigsrock]

You will need to cut and stretch the frame I think if you go with the four runner frame. But if you don't mind cutting and extending frame, break lines, fuel lines, electrical, then go for it.

I would say you probably need a extra cab short bed at the least.

I would try to find some info on the chniooks wheel base length so you know what kind of length you are looking at.

Mine I beleive is based on a 2wd LWB pickup frame. I want to say mine it is at least 107" but may be longer. I will have to check the WB when I get home for you.

here is mine. Bonanza camper. https://forum.ih8mud.com/79-95-toyo...4x4-sas-1986-toyota-chinook-camper-build.html still in progress.

 

[4RUNNY]

Thank you for the input KLF and Meigsrock,

I had the opportunity to take several measurements on the Chinook and it appears the difference between the distance from the center of axle to the rear of the cab (the hardtop line on the 4Runner) is about 9 inches. I'm still playing with the idea...

For mounting the Chinook Cabin on a SWB frame I can think of several options of varying severity that might work:

1. Extend frame 9.5 inches directly behind cab.

2. Mount Chinook cabin directly on the SWB frame --> This could be achived by drilling new mount locations in the Chinook frame and floor 9 inches forward to match the existing SWB locations, lengthen the Chinook wheel wells forward to allow for tire travel.

3. Widen the chinook cab opening, so the Chinook could be pushed forward 6 inches to near the door line on the 4runner. This method would require adjusting the Chinook mount locations as in option 2, but only about 3 inches forward. Minimal wheel well adjustments.

4. Major chinook fiberglass manipulation (adjusting the front of the chinook cabin 10 inches back so the chinook will fit mounted on existing chinook mount locations on SWB body mount locations). This would decrease the size and tail stickout of the chinook cabin.

5. Push axle and suspension components 9.5 inches back and adjust chinook mount locations 9 inches forward.

For my budget and ability, option 1 and 5 really aren't possible, but I'm playing around with the other options. I know it would probably be better to just buy a LWB truck, but they are hard to find up here and the whole idea would be to retain my pet 4Runner for this project. Keep in mind that my 4runner already has a full pack of 63 inch chevy springs in the rear end for heavy expidition loads. I think option 2 might look and behave a bit funky with the axle so far forward relative to the rear end of the truck, but would maybe be the easiest. I'm going to propose these ideas, and see if one might be feasable. Hopefully the chinook in mind will still be available when I finally decide to go through with it...

-Brian

 

[GRM]

2x3 tubing will hammer into the rear part of the frame on your 4runner Extend the frame that way, and move the rear axle back. Drill some holes, weld in a round tube crossmemebr, and your done. Might as well put longer springs on it at the same time.

In fact, if you really want to get creative, you could run an f-150 spring backwards, or a 63" chevy spring, use the stock front hanger, then mount the axle 1.5" forward on the perch. This will move the axle 9.5" back.

See pics of when I extended the frame 6" on my '86 mini.

 

[KLF]

Geez, couldn't you find any longer shackles?

 

[4wanderer]

Hello all I'm a newbie on this site but I'm an avid toyota fan I own two first generation runners 86&89 I am thinking of a chinook build on one of them probably the 89 I'm looking for ideas from those who have gone down this road. Any suggestions? I'm thinking of building a floor rack such as swcruiser did on his PC to chinook build. I'm in the research phase and need all the help I can get. So all replies are welcome. Thanks guys.

 

[meigsrock]

As cool as these are I think it is probably way more work than worth it. If you find a good chinook and want to fix it up, that is one thing but to mount the camper portion on your truck is a lot of work.

I think you would be better off with a pickup to start with instead of 4-runners.

I also think for most peoples needs it would be way easier to just buy a pickup and put a small pop up camper in the back of it and secure it well instead of putting a chinook camper on a truck.

 

[4wanderer]

I've somewhat shopped for a lwb truck however I bought this 89 runner years ago for 200 bucks so I don't have anything invested in it. And the wife wants the camper also as we do a ton of outdoor activity. So I'm mulling over everything and just thinking. Thanks for the input though especially since your kinda on this type of project

 

[busmup808]

I just sold my Landcruiser 4 weeks ago to do the same thing your thinking. Instead of going your route, I was going to buy a Chinook, Bandit, Sandtana, etc. all 3 mentioned were built on a mini truck frame and not long and heavy as the longer/heavier big RVs out there. All you would have to do is a 2wd to 4wd conversion. A lot of time you would save than going the route you want. Then you have to consider that the smaller the rv is, the less things its going to have. The main thing for me was the bathroom. Those 3 that I mentioned, had everything you needed to explore but the bathroom.

Long story short, I bought an RV with everything you need to stay out of the elements. I bought everything to do a 4wd conversion. Good luck on your decision. Aloha.