Allis 7000
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=210089
Printed Date: 04 Apr 2026 at 9:06pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Allis 7000
Posted By: Empirestate
Subject: Allis 7000
Date Posted: 16 Feb 2026 at 5:56pm
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hello all, New member here. Been a lurker for a while and have gleaned a lot of useful information. Now I have a problem I could use some help. 1978 Allis,7000. It does not have differential lock, but all of a sudden it acts like it does. Just driving tractor only it steers, but with a round bale on the 3 pt. You can't turn it, not even using the breaks. I suspect something is wrong in the final drive, but what? Thanks for any help Bob
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Replies:
Posted By: DrAllis
Date Posted: 16 Feb 2026 at 6:18pm
| The differential is locked up. There is a dipstick directly behind the cab under the SMV sign. I'm guessing your PTO seals have been leaking oil and that compartment is very low on oil. Wheels have to come off. Axles get pressed out of their tubes. Brakes/brake housings come off. Lift arm housing comes off next. Then, you are down to the differential with the ring gear. Cab might have to be lifted a little, but not removed. |
Posted By: Empirestate
Date Posted: 17 Feb 2026 at 4:56am
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thanks Dr., Are we talking major damage or parts not sliding as they should? I did pull the dipstick, it was low but Still showed oil on the stick. Thanks again, Bob
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Posted By: Empirestate
Date Posted: 17 Feb 2026 at 5:05am
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dr. Allis, I should have asked am I going to do more damage if I were to keep using it? I still have to feed cows Until the weather improves, also don' t have heated shop.
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Posted By: DrAllis
Date Posted: 17 Feb 2026 at 6:28am
| More damage?? Maybe and maybe not really. The affected parts are already junk. If you must continue to use it, overfill it 2 or 3 gallons from the top mark on the stick. Maybe even overfill with diesel fuel to act like penetrating oil inside the differential. It will not hurt doing this. |
Posted By: Empirestate
Date Posted: 17 Feb 2026 at 6:32am
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thanks dr. Won't use more than I have to . What am I looking at for ruined parts.
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Posted By: DrAllis
Date Posted: 17 Feb 2026 at 7:38am
| Four seized pinion gears inside the differential case and a ruined cross at a minimum. I only remember having to repair one over the years and it had 6K+ hrs on it and had done a fair amount of plowing in its iifetime. |
Posted By: Mikez
Date Posted: 17 Feb 2026 at 7:43am
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Welcome to the forum. Goodluck. Where abouts are you located
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Posted By: Lynn Marshall
Date Posted: 17 Feb 2026 at 8:21am
This is the differential carrier from an 8030 a few years back.   
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Posted By: DrAllis
Date Posted: 17 Feb 2026 at 8:23am
| That's pretty cool, Lynn. For sure when he placed it in "park" on a hill it rolled another couple of feet !!! |
Posted By: Les Kerf
Date Posted: 17 Feb 2026 at 8:26am
Yikes!  |
Posted By: Empirestate
Date Posted: 17 Feb 2026 at 3:30pm
| thanks again DR., i'll post back in several weeks when I get it apart. When weather allows. I'll try to use a different tractor if it will pick them. Mike , I'm in the southern finger lakes area. |
Posted By: Empirestate
Date Posted: 17 Feb 2026 at 5:43pm
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Dr., Been looking at the service manual and it talks about splitting tractor. Where does the differential assembly come out? Thru the rear 3 pt. Lift housing opening or thru the front which would mean a split. Thanks, Bob. Just trying to get a handle on what I have to do and plan for.
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Posted By: DougG
Date Posted: 17 Feb 2026 at 6:34pm
| Not sure of your mechanic skills- but maybe better off getting the complete rear off a parts tractor,, |
Posted By: Lynn Marshall
Date Posted: 17 Feb 2026 at 9:06pm
| No split required for taking the differential assembly out. Do as the Dr. says and roll it out the back, lift housing area. |
Posted By: Mikez
Date Posted: 17 Feb 2026 at 11:04pm
| Oh ok other side of state. We’re next to Hudson River |
Posted By: Empirestate
Date Posted: 18 Feb 2026 at 3:50am
| thanks for the conformation Lynn. Not too far Mike. |
Posted By: SteveM C/IL
Date Posted: 18 Feb 2026 at 7:27am
| So how does that happen? Not using diff lock when needed and spinning the crap out of one wheel? To low oil too? |
Posted By: Empirestate
Date Posted: 18 Feb 2026 at 10:36am
| steve, doesn't have differential lock, not spinning the crap out of it, just feeding hay. Slightly low on oil, but still above the low mark on the stick. |
Posted By: Acdiesel
Date Posted: 18 Feb 2026 at 11:08am
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I assume you have the same issue while going in reverse? ------------- D19 Diesel,D17 Diesel SER.3 2-D14, 2-D15 SER.II WF/NF D15 SER.2 DIESEL D12 SER.I, D10 Ser.II 2-720'S D21 Ser. II Gmc,caterpillar I'm a pharmacist (farm assist) with a PHD (post hole digger) |
Posted By: Empirestate
Date Posted: 18 Feb 2026 at 12:32pm
| acdiiesel, yes it doesn't matter which direction. Just gotta face the music and tear into it. |
Posted By: DrAllis
Date Posted: 18 Feb 2026 at 3:58pm
| Differentials love to be flooded with oil. Overfull is always better than low on oil. in-furrow moldboard plowing used to be the worst thing for a differential, especially if the land wheel didn't have enough weight/traction. I've fixed a couple of 7030-40's over the years and it's always been due to LOW oil levels. You can have one of those tractors 5 to 8 gallons low on oil and all the hydraulics and steering work just fine. Too many neglected or foggy sight glasses. I always fill to the top glass plus a couple of gallons if it's mine. |
Posted By: Empirestate
Date Posted: 18 Feb 2026 at 5:29pm
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I hear ya Dr. You can bet i'll be on top of it after this. Wasn't even being work hard, put 3 bales of hay out every other day, other wise just sitting there. No noise or anything, just one day it started doing it
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Posted By: DrAllis
Date Posted: 18 Feb 2026 at 6:26pm
| How many hrs are on the tractor?? You haven't owned it all its life have you ?? |
Posted By: Empirestate
Date Posted: 18 Feb 2026 at 6:57pm
| A little over 5000 if it's correct.I've only had it about 5 years, but it does what I need. |