Solid Axle Swap BS Thread

I posted in here a while back about my truck driving like absolute shit on the road... well I think I finally figured out why. Someone set the tie rod up with almost 1" of toe OUT I've been told to set it to about 1/8" toe in, anyone have some input?

 

I literally did mine yesterday. I did 1/8" toe in and just test drove it and its handling very well now.

 

Awesome! Road manners is my biggest complaint with my truck. I will take the long way home from work to avoid highway speeds. THe only issue now is that I can't get the jam nuts on the tie rod loose... I need a torch

 

In case there are any curious minds

 

I just don't understand why you guys have problems with the inputs on the chain case. I don't, haven't and never will. Love my setup and all those i've installed and none have had issue's with the input on the chain case. Toyota has been using that same input design for over 30 years now and haven't had any issue's with it. So if thats the case why now when you use a crawler box? Could it be the coupler instead. Hmmmmmm?

But, if some have had wobble issues then the coupler itself was the problem. not the input shaft. There are different couplers for the 4.0 taco's and for the 2.7, 3.0 and 3.4 taco's. ask me how I know. If you run one in your 4.0 designed for the 3.4 then it'll be too tight and will cause preloading of the bearings on the crawler. If you use the 4.0 coupler on any of the other motors it will be too loose and frett the input on the input of the t case.

Not all 23 spline inputs in the chain case's are the same. The press fit on the 4.0's is much tighter than the others and because of this there is a need for a different coupler.

Small details most people don't know about, not even most of the after market guys know it because they haven't taken the time to look into it. Thats why I wont cobble together parts from Marlin, Trail Gear, and Inchworm together to build a box anymore.

 

Wyatt: I think I have beat this horse on a few forums, but my issue was with the marlin coupler, lack of guidance in installing these crawlers and partly with the short input. My coupler fretted and striped because A) it was known in the shop to goop anti seize on the, inputs to limit fretting however it's not written in any literature from the mfr. B) the inherent flaw with the crawlers since its a bearing only supported on one end so it wobbles a bit no matter what, and C) the tacos short input can contribute to that wobbling. I had one failure, ran the chain drive case for another year with no probs and swapped in a lefty. So it was a combo of ABC that took out mine, obviously you can get them to work trouble free if you take some steps to prevent it. I just like to give out my advice and others to learn from my mistakes, goop that input in antiseize and do regular maintenance and if you see red gear lube, drop the case cuz she's a fretting!!

You told me about the anti seize trick btw on Ttora.

 

Agreed. There really needs to be some instructions on these things. I tried to make some but companies kept changing what front adapters they used and rear adapters, then the coupler design came into play and finally I gave up until Marlin decided to go back to their own designs.

The anti seize is really just a band aide for the coupler issue, not the short input. My truck was the first 2nd gen to have a crawler and when it was installed it ran for almost two years without anything on the front input of the t case. We ran it dry on that input. The only reason I pulled it was because marlin had made some changes and wanted to test them on mine. At that point is when I first heard about fretting and then talked to Mike and he said to use anti seize. I started using it then ( actually just marine grade grease ) and started to spread the message.

The real problem is getting the couplers made correctly for the different front inputs and that has only been discovered with-in the last year after I started doing research on the chain case's and another project I have.

If you go back to the first type of 23 spline inputs they didn't have a pressed on coupler. They just slid on a pressed coupler on the back of the transmission. Then some had the pressed coupler on the t case input. These two inputs were very very close and would work with the same coupler in a crawler box. When the 3.0 engine came out and the 3.4's came out the t case's had pressed on couplers if they were automatics and could use the same coupler as well. Enter the 2nd gen taco's and the 120 series trucks. they had a super tight fitting input coupler design and the way they made the fit tighter was by having the valleys in the input "raise" up a bit in the middle of the splined section. It's about a 10,000 of an inch amount but just enough to cause issues when trying to get the input onto the internal coupler of the crawler. Everyone thought you could make a coupler to fit all the inputs but we have since found that when doing the 120 series trucks there needs to be a different coupler even though it's just 10,000 of an inch difference.

As many times as my crawler has been out of my truck to have improvements done to it I've never noticed any fretting issue's at all and my crawler has seen all of the improvements that Marlin Crawler has made to these things through the years and the input on my t case looks just as it did when we first installed it years ago. Albeit with a bunch of anti seize ( Grease ) on it now.

For those that worry about the short inputs...... no need to worry. The fretting issue is a very very small amount given the thousands of crawlers that have been made and sold by back yard mechanics and the five or six companies that make them. ( Yes, there are that many ) and the fretting issue has nothing to do with the input size of the t case anyway. It's actually the same size as the original input of the very first dual case setup made in Iceland where marlin bought the rights to the very first "Crawler Box". Here is the stock gear driven 23 spline input.



In this picture you can see the 23 spline input ( the smaller one ) which is the same size as the stock geared 23 spline but it's not broached straight like the geared case. It has a curve to it in the valleys for a pressed fit. Even the 22 spline six speed input is straight so it just slides off of the back of the transmission where the coupler is. In the next picture is the 23 spline input from the 4.0 Tacoma with the stock coupler just sitting on the input splines. I had pressed it off and sit it back so that some one could see the orientation of the stock coupler.





The way the coupler in the crawler is designed, this input shaft sits squarely in the section of the coupler that is supported by the pocket bearing. If it's using the correct coupler for the input it won't wobble around and have fretting issues. If the incorrect coupler is used you could have fretting issues or worse it could be too tight and you could have crawler damage.

Anyway, just some information I have found out by researching these things to death and by working with them to come up with better products.

 

Good stuff. I built mine in 07, and it stripped out almost a year to the day of install in 08. So there has been a lot of advancements since then. When I bought mine the two main ways of sealing the front adapter was Jim's sealed coupler and marlins goofy barrel thing that pressed against the front plate. Evreythng else was stock mini truck stuff except for the mc09 adapter. Side note I think they need to bring that adpater back, those 360* adapters look like they bring the suck with possible failure points.

I see you reference the stock mini truck 23 spline input, wasnt the fretting and strength issue the reason why marlin developed the total spline input? That's the main reason why I went with the lefty along with I like how the mc07 adpater shares fluid with the tcase.

 

The reason they went with the total spline input was because of input failure. The stock 23 spline inputs would snap right off at that section right behind the splined portion.

In the one picture that has the input shaft with the coupler sitting on it you'll notice that i've whited out something in the back ground. It's a prototype but lets just say you wont be seeing any of those 360 plates anymore.

 

H8U

 

Who buys an fj80 axle?!?!? Don't you know you can't wheel on anything less than a d60 without things exploding!!


Get a plasma cutter or a torch, cutting those brackets off SUCKED!! That metal is thick!!!

 

You know now would be a perfect time to link the rear....

 

Oh I know. There's this little thing called money.... I need more of it.

 

What i should have done with mine, and perhaps you can run with his, is to keep one of those link brackets (i was thinking the one above the diff) and use that as a anti wrap bar bracket. All you would need is to fab a lower bracket and build a bar. I was going to do that, made a mental note, then cut if off a few days later by accident LOL.

 

Those 80 series axles are pretty stout. I'm actually getting ready to do a build that has two of them with the LC9.5 diff's in them. Going into a first gen Taco. Gonna be sweet.

 

Once I get the 80 rear in I'll have 9.5's front and rear too. My fj60 front has taken a beating so far!

 

Not a bad idea but I have seen another style that I liked so I'll probably go that route when the time comes.

 

I was being a smartass! I have one in my truck already and I am building a front axle now with a 9.5" diff. Cool axle for sure!

I just have to get it to stop pukeing rear u joints.