7G and 7G-B
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=106249
Printed Date: 29 May 2025 at 3:06am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 7G and 7G-B
Posted By: DMiller
Subject: 7G and 7G-B
Date Posted: 16 May 2015 at 9:11pm
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As most here already know, I am the somewhat proud, or not, owner of a 7G, one of the last built and supposedly with FA markings when new. It has the typical for the time hand clutch controls and steering brakes but if you do not use the clutches just brakes. All is mechanical/hydraulic. To make a long story longer and more boring I had chance to look at the steering mechanism on a 7G-B, of course it is predominantly a Fiat product but used the same final and trans as my older unit just has full foot control of the steering. The second tractor I bought for parts had been cobbled together to do similar but they failed to add the third brake pedal to stop the unit without applying clutches. I feel I am about to embark on a conversion to the later style brake control and free my hands on the remaining controls, the decelerator will need to move but can go where I choose, just have to set down and figure out the over-running linkage assortment to make three pedals work as units in common. I am also going to try to improve the single bucket control built two seasons ago. Have looked to the old illustrated parts guides with those as template. |
Replies:
Posted By: HD6 Merv
Date Posted: 17 May 2015 at 2:24am
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afaik Dave the series B was a AC product; most parts are still the same as 7G; except for the 3500 engine. The controls for steering and bucket are an 'evolution' over the machines design period. ------------- tits tyres and tracks they all cost you money |
Posted By: Mactractor
Date Posted: 17 May 2015 at 3:38am
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The AC engineered machines in production when Fiat took over all got the Fiat Allis decals without any Fiat engineering in them. When Fiat did apply their engineering to the line, the loyal AC buyers began to drift away to Komatsu and others rather than tolerate the pathetic product from Fiat |
Posted By: DMiller
Date Posted: 17 May 2015 at 5:25pm
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I really like the single stick bucket control I built but needs 'honing', the style of linkage on the B seems simple enough to duplicate. I did see the earlier version 7G-B, did have a similarity to my own machine but had the 3500, were these any easier to work on than the Lanova 7000? Did they do any better repair wise? |
Posted By: Mactractor
Date Posted: 17 May 2015 at 7:23pm
| The Lanovers were the Buda`s before the AC thousand series engines, and had injectors in the side. The 6,7,10, and 11000 engines gave very good service for their owners, and it would be a tall statement to say 3500`s were a better engine in any respect. |
Posted By: Lazyts
Date Posted: 18 May 2015 at 12:03pm
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As Mac stated, the 7G-B was all Allis Chalmers. I've got a picture somewhere of a dealer meeting in the spring of 1974, just after the merger, in which both the 21C and 31 tractors appear. This tells me that Fiat developed NOTHING in the tractor line after 1974, except adding european product. The only thing I can see that they might have developed was the twin engine 262 scraper.... It's really too bad, they might have been a contender.
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Posted By: Lazyts
Date Posted: 18 May 2015 at 12:08pm
| As also stated, the small AC engines gave good service, but the 844 really let them down in the big stuff- scared people away from the 945 loaders, 21 tractors and the big scrapers- from what I've heard, they rarely made it past 5000 hours. A Cummins engine might have been a good fit. |
Posted By: Lazyts
Date Posted: 18 May 2015 at 12:32pm
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Posted By: Lazyts
Date Posted: 18 May 2015 at 12:46pm
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Tractor line: (from left) 41B, 41, 31, 21C, 21B, two 16Bs, 14, 11B, 10 and 8 Wheel loaders: 945, 745HB, 745B, 645B, 605B, 545B, 345 Not sure of crawler loader models, but looks like 7GB and 12GB are both there Graders: 65, 100C, 150C, 200C Motor Scrapers: 260B, 261B, 460C
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Posted By: Mactractor
Date Posted: 18 May 2015 at 5:09pm
| Good old brochure Trev. I agree Cummins 855 was the solution to the 25000 engine troubles. Some of my Australian neighbours repowered their 460 and 562 scrapers with 8V92T`s which made them happy modules (when diesel fuel was dirt cheap) |
Posted By: mudlord
Date Posted: 29 Oct 2017 at 5:55pm
| I have just purchased a Allisfiat 12GB track loader , i had a heavy equipment mechanic change all fluids and filters. It cranks and runs great , but he said the steering clutches are worn out , it will drive fine but will barely turn one direction . I am trying to find and order a clutch kit for this unit but i am having a hard time finding what i need can some one on here give me a little advice please !!! |
Posted By: Ian Beale
Date Posted: 29 Oct 2017 at 10:03pm
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Do the brakes work? If if is like a FA 10 they run off the same circuit as the clutches and when working properly you should be able to feel the pedal pulsate when applied hard. There is a filter under the driver's left foot on the front of the bevel case. If the oil level in the bevel gear case (from where it pulls oil for those circuits) gets very low you can get some interesting effects of not wanting to steer. Today - I was assuming it was a Fiat type 12. If it is an Allis type ignore this |
Posted By: Lazyts
Date Posted: 01 Nov 2017 at 9:21pm
| Would check brakes first, and adjustment of linkages, as both the steering clutch and brake are on the pedal, correct? Will each track stop independently when under load? Worn out clutches would make it want to steer one way or other all the time. |
Posted By: DMiller
Date Posted: 02 Nov 2017 at 4:36am
| Clutches worn cannot do this, bad seals on clutch disengagement mechanisms can. With my 7G the system uses a secondary hydraulic pump, engine driven to release the clutches, if weak will release them poorly, if damaged will not release at all, if seals are bad at clutches actuators will cause as you indicate. I have rebuilt both my actuators this does require clutch removal and replaced my steering/brakes pump. |
Posted By: DMiller
Date Posted: 02 Nov 2017 at 5:41am
| If anyone has parts for this is Minnpar, Minneapolis. If they do not have the next step would be to disassemble and take the components to a hydraulics shop for seal matchup, will be Teflon or another type hard quad ring seals. There are hydraulic hoses inside the clutch cases on these, from the actuators to a thru fitting then to the controls assembly, these could be bad. |