F78 Rocky Transmission issues

DR - Doctor
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Location: Ballarat, VIC

F78 Rocky Transmission issues

Unread post by DR - Doctor » March 9th, 2012, 7:32 pm

Hey Guy's,
I am new to this forum, but have followed it of and on for a while as it makes for good reading & learning...Now I am in need of some advise..........
Have a 1999 Rocky F78 with 280,000k on it am having trouble selecting 2nd Gear & coming Back from 3rd... it was perfectly fine one day then the next day it started, no gradual issues almost instantly :confused: . Have been told that it possibly could be that the lock nut at the back of the output shaft on the Transmission could be loose, apparently this is common. Has anybody heard of this before??

shambles
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Joined: September 10th, 2009, 8:05 am

Re: F78 Rocky Transmission issues

Unread post by shambles » March 10th, 2012, 4:28 pm

Don't know about it happening overnight, I'm pretty sure you just dump the oil, drop the transfere case and tighten up with a new nut using a rattle gun. HAppy to be provn wrontg though.

Have a look in outer limits, I sure I've read a write up on it somewhere.

DR - Doctor
Getting to know the place
Posts: 10
Joined: March 9th, 2012, 7:10 pm
Location: Ballarat, VIC

Re: F78 Rocky Transmission issues

Unread post by DR - Doctor » March 10th, 2012, 8:26 pm

Thanks shambles... Much appreciated,
More than likely you are correct could have been a little...... notchy prior... but from that overnight it simple will not go back to 2nd from 3rd without some well timed double clutching and on the up change revs & good timing also. Anyway thanks again I am keeping fingers crossed it is the problem.. Cheers

P.S.
Just sussed out Outer Limits as you suggested.. took me a while but found the thread you referred to but alls good!!!

Thanks Again... DR

DR - Doctor
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Joined: March 9th, 2012, 7:10 pm
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Re: F78 Rocky Transmission issues

Unread post by DR - Doctor » March 13th, 2012, 2:36 pm

Looks like Nut and Gasket have to be source out of Japan.... Toyota Spare Parts can't get from Diahatsu Australia so will have to Cut my own Gasket and locktite the exsisting Nut unfortunately. Should be okay for a few more years... though.

DR - Doctor
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Joined: March 9th, 2012, 7:10 pm
Location: Ballarat, VIC

Re: F78 Rocky Transmission issues

Unread post by DR - Doctor » March 20th, 2012, 3:02 pm

Whoo Hooo!!! All fixed... Nut was barely finger tight apparently, selecting all gears nicely now.. :) Thanks for your Help!

Cheers DR

shambles
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Joined: September 10th, 2009, 8:05 am

Re: F78 Rocky Transmission issues

Unread post by shambles » March 20th, 2012, 10:47 pm

well done.

DR - Doctor
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Posts: 10
Joined: March 9th, 2012, 7:10 pm
Location: Ballarat, VIC

Re: F78 Rocky Transmission issues

Unread post by DR - Doctor » March 21st, 2012, 8:35 am

Thanks..

Now just need to decide whether to keep it and do a bit of a build as I have had it since new and is still very tidy... or whether to upgrade to a late model of some sort and spend the $$$ on that, As we want to do some touring and see more of the OZ in the not to distant future..
Lot of choices out there, just need to figure out what suits me...

Cheers

gregp50
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Re: F78 Rocky Transmission issues

Unread post by gregp50 » May 30th, 2012, 9:19 pm

Dam had the same problem but turned out the box was reconditioned and the output shaft was stacked a bit to hard and it fractured the end of the output shaft which resulted in the shaft losing half its thread and then the nut come undone.
Saying that it still drove in all other gears ok except 2nd gear, anyone know what happen if ya kept driving with this output shaft nut undone.

DR - Doctor
Getting to know the place
Posts: 10
Joined: March 9th, 2012, 7:10 pm
Location: Ballarat, VIC

Re: F78 Rocky Transmission issues

Unread post by DR - Doctor » June 9th, 2012, 3:34 pm

Hey... I only drove mine for about 500-1000k once problem clearly presented itself so hard to say. But seeing the difficulty I was having with changing up to & down to 2nd gear I would say it would only be a matter of time before syncro's & 2nd gear would suffer.
As you may know the nut can't dislodge from where the transmission & transfer couple together... but again being lose and everything moving around more than it should can only do more damage long term.

Just hoping using the existing nut does the job as was not comfortable re-tensioning to 226-264 N.m as required..

Cheers

danielk
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Re: F78 Rocky Transmission issues

Unread post by danielk » July 1st, 2012, 8:26 pm

The same nut came loose on my f75 but did considerable damage to a few of the gears. completely stripped the thread off the shaft so had to get a new shaft a few new gears and a bearing/synchro kit. was $2800 about 5 years ago

gregp50
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Re: F78 Rocky Transmission issues

Unread post by gregp50 » July 13th, 2012, 9:26 pm

Ouch yep fixed my gearbox, i ran overhaul kit through it $450 and put a second hand output shaft from a old gearbox i bought. New output shaft that holds gears on are worth $550 and was thinking about putting a new dog cluster assembly with reverse gear on it but that was $600 and a 3 week wait from japan. The output shaft i took out was well within measurements but the end of it where the 32mm nut goes over was fractured off to bad.

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