Outer Limits 4x4 Board

I have a client with a 100 series with an R151 F 5 speed.

He has been told that this gearbox is weak for towing due to one of the shafts having had its spline changed from normal 20 plus count spline to a coarse 3 spline. this will cause failures when towing heavy loads apparently and he is going to tow 3.5t around Australia.

Can anyone enlighten me about this and what his options are for overcoming the issue.
He has been quoted $5k for RR gearbox, replace shaft with properly splined unit and re bearing.

Cheers

I'm not an expert here, but I thought they were the gearbox to have. R series boxes are all pretty much the same inside, just different ratio's.. R154 is what is in the twin turbo supra which is considered an extremely strong box in the performance car circles. R150F is in V6 4-runner, and R151F is in the cruisers. I have heard a suggestion that 5th gear can wear when it has excess load for long periods, and that proper procedure is to use 4th for hills. This I assumed was common sense.

I have friends and family that tow vans and trailers behind their cruisers and haven't had a gearbox issue.

What he has been told sounds like a gearbox shop wanting to make some $$$.

If an expert comes along though, take his word over mine.

It seems this is the problem, the collar in the pictures only engages the spline over about a 15mm length, which presents as a weak point.
A new shaft can be fitted where the collar is integral to the shaft.

h150 and h151 are the towing gearbox you want.
one has lower first gear than the other, making hill starts towing perfect, as lots of cruisers have a realy slow first gear.

your better off getting in lcool forum.
plenty of info in the gearbox... mostly the 100 series section.
its a sticky thread at the top, easy to find.

their is better r gearboxes.
early ones or later ones were better.

but if your towing alot the h series is the pick.
dear but strong to handle the torque of the TD engines.

some gearbox places can have tricks up their sleeve to make said box stronger, finding those places is the hard part.

i hear all the time, i just got it rebuilt.. and it blows up again..
strong box arent cheap. but will last.

That's his conundrum at the moment, to take the rebuilders word and spend $5k to get it rebuilt with new shaft or modify a factory stock 100 with a H series that he will use to tow a van around Oz.

I am trying to research it for him but don't want to give him bad advice.

Cheers

I'm sure terrain tamer have replacement stronger parts for gear boxes and the one piece unit you mentioned earlier, give them a call and see what they have.

Mark.

Yes I advised him to get onto Terrain Tamer, he is after a full rebuild.

He has been quoted by 360 gearboxes and Diffs in Bayswater Melbourne. They have a pretty good rep from what I can tell.

Cheers

Struth, have a look on LCOOL 100scool pages, there is heaps off info on gearbox conversions. The H150F box from 80series is the one to get.
There is no shortage of failures with the r151f.
I have a 105series and have a H150F in the shed ready in case.

If they are looking at a rebuild with aftermarket parts, better off upgrading to the heavier box, especially for towing or turbo charging.

Thanks for the info guys, we are considering fitting a H151F to it since he is doing a complete lap with 3.5t caravan.

Does anyone know if there are any tricks and pitfalls to this?

Will the sticks fit inside the cab without major mods?

Will the transfer from the H151F mean the drive shafts need to be modded?

Will the existing cross member fit the new trans?

Will the speedo hook up?

etc?

Just thought I would ask if anyone knows before spending several hours researching.

Cheers

struth, go to lcool 100scool, there is a sticky at the top of the page with comprehensive info on what will be required.


link added
http://www.lcool.org/forum/viewtopic.ph ... 93f49b340a

h150 is the better option, first gear is lower which will help with the 3.5t towing, especialy if the donks a 1hz..
easier starting off the lights, or hill starts.

Hi shaun remeber me
we sell and u can buy r151s for around $2100 genuine

and when I say 2100 it maybe plus gst depening how generous i feel and there out of a 1HZ and non change over and there a genuine toyota box

Do you do H151s ?

And your spindle arrived today.
So about another 8 1/2 weeks before you can have your car back