Gearbox for Thwaites dumper poss Orion

Discuss dumpers here

Topic author
Bolton
Posts: 8
Joined: Tue Oct 01, 2019 11:52 am
Real name: Matt
Been thanked: 2 times
Flag: Argentina

Gearbox for Thwaites dumper poss Orion

Post #1 by Bolton » Mon Apr 13, 2020 3:57 pm

First post on the site. I've done car repairs over the years but dumpers are a new area for me so hope someone can chip in with advice. I'm looking for a replacement gearbox for my mate's dumper. Its a single cylinder Petter 6.75hp powered Thwaites maybe an Orion as below. I can post more pictures if it would help. The engine drive is toward the rear then there's a chain drive in a case that goes across to the box which takes the drive forward to the diff at the front.


Image

The gearbox I'm looking to get is pictured below but seller says its not likely to be a direct fit to a chain drive setup.( I also have a Newage 40M box if anyones interested)

Image

Hope above makes sense. WIth thanks in advance , Matt


Matchless?58
Posts: 196
Joined: Sun Oct 27, 2019 1:41 pm
Real name: Chris
Has thanked: 14 times
Been thanked: 53 times
Flag: Great Britain

Re: Gearbox for Thwaites dumper poss Orion

Post #2 by Matchless?58 » Mon Apr 13, 2020 8:39 pm

Hi Matt
I can confirm that you have a thwaites Orion .
The gearbox fitted to these was I believe the newage 40m . No doubt someone will be along to correct me if I'm wrong .
Have you tried the 40 m to the dumper ? Why won't it fit ? It might depend on the serial number . Some of the boxes on these old dumpers are reversed fitted .
Let me know how you get on I would be interested to know .
Cheers Chris


Jeremy Rowland
Moderator
Posts: 8667
Joined: Sun Aug 05, 2007 8:36 pm
Real name: Jeremy Rowland
Has thanked: 1867 times
Been thanked: 1688 times

Re: Gearbox for Thwaites dumper poss Orion

Post #3 by Jeremy Rowland » Mon Apr 13, 2020 8:51 pm

Hi Matt and welcome :wave: you should find plenty of help on here, good luck with the dumper. :thumbup:

Jeremy


Topic author
Bolton
Posts: 8
Joined: Tue Oct 01, 2019 11:52 am
Real name: Matt
Been thanked: 2 times
Flag: Argentina

Re: Gearbox for Thwaites dumper poss Orion

Post #4 by Bolton » Mon Apr 13, 2020 10:18 pm

Thanks Jeremy for encouragement!

Matchless - thanks for advice. I will go over the road in the next day or two and get some better photos and take my Newage box for better comparison - maybe it could go on as you suggest, and it seems to be in good condition which is more than can be said of the current box on the Thwaites which is hanging on with ad hoc welds and apparently has to be "manually" held in gear on the stick to get the dumper to make progress at all!

Will post back on this thread soon.. Cheers again, Matt


cobbadog
Posts: 475
Joined: Thu May 17, 2018 6:08 am
Real name: John
Location: Coopernook. NSW. Australia
Has thanked: 302 times
Been thanked: 138 times
Flag: Australia

Re: Gearbox for Thwaites dumper poss Orion

Post #5 by cobbadog » Tue Apr 14, 2020 12:40 pm

Welcome to the Forum Matt. Sounds like your taking on a challenge but a fairly straight forward one. The first thing to check is that the replacement box works in the same direction as the one coming out as already mentioned. Once your happy with that I would be a safe bet that it will bolt up but just incase take a tape measure with you to get an overall length, height and count the bolt hols around the bell housing.
Cheers Cobba


Topic author
Bolton
Posts: 8
Joined: Tue Oct 01, 2019 11:52 am
Real name: Matt
Been thanked: 2 times
Flag: Argentina

Re: Gearbox for Thwaites dumper poss Orion

Post #6 by Bolton » Wed Apr 15, 2020 12:08 am

Maybe I should just take the dodgy gearbox off the Thwaites but as mentioned yesterday I'll post up a few more pictures as new to this

Here is my spare 40M gearbox:


Image


This is the chain assembly, clutch on RHS at rear of engine:


Image

This is the label on the current gearbox:


Image

This is the layout (Matchless - I guess you know this model anyway)



Image

HTH thanks again in advance on any more thoughts..


cobbadog
Posts: 475
Joined: Thu May 17, 2018 6:08 am
Real name: John
Location: Coopernook. NSW. Australia
Has thanked: 302 times
Been thanked: 138 times
Flag: Australia

Re: Gearbox for Thwaites dumper poss Orion

Post #7 by cobbadog » Wed Apr 15, 2020 8:47 am

I see an issue with the 2 gearboxes and that is the clutch arm is on the opposite side. Not sure if this is a simple fix or not but you would think it is an easy fix.
Cheers Cobba


essexpete
Posts: 4059
Joined: Fri Jul 13, 2007 12:43 am
Real name: essexpete
Has thanked: 849 times
Been thanked: 680 times

Re: Gearbox for Thwaites dumper poss Orion

Post #8 by essexpete » Wed Apr 15, 2020 10:01 am

Is the main problem in swapping lying with the completely different clutch type/set up? I am assuming the Orion is similar to the Nimbus with the gearbox chain driven from a brake drum like clutch on the engine output?


Topic author
Bolton
Posts: 8
Joined: Tue Oct 01, 2019 11:52 am
Real name: Matt
Been thanked: 2 times
Flag: Argentina

Re: Gearbox for Thwaites dumper poss Orion

Post #9 by Bolton » Wed Apr 15, 2020 11:36 pm

(editied post at 10:20 16th April please reread as relevant - thanks) Thanks cobbadog and essexpete for replies. I don't know the Nimbus but yes its definitely chain driven to a clutch but on the gearbox end, the photo I posted of the transmission from underneath is not that easy to work out (unless you took it) but on the RHS there is a simple pivot setup that swaps the clutch pedal movement to a thrust type push inward that I assume works via a thrust bearing to operate the clutch.

For this Thwaites dumper repair hopefully just the gearbox (without the bell-housing) will bolt on ok as clutch should work O.K. anyway.

There have been two mentions from you on the posts of reverse fitted gearboxes which I'll look at.

Will post again when I've taken the gearbox off.

Thanks all for now but please post again if you have any other ideas on it.


Daves dumper
Posts: 2
Joined: Thu Apr 11, 2019 5:48 pm
Real name: Dave
Flag: Great Britain

Re: Gearbox for Thwaites dumper poss Orion

Post #10 by Daves dumper » Fri Apr 17, 2020 1:46 pm

Hi, the thwaites tusker uses a similar setup with chain drive gearbox.
The makers plate on your pic looks similar to mine and I may have a spare gearbox. If you can post a pic of the gearbox in-situ I will check what I have.


Return to “Dumpers”

Who is online

Users browsing this forum: No registered users and 8 guests