7045 Crank Broke - Rebuild or Swap?
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=177180
Printed Date: 24 Jun 2025 at 11:13am
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Topic: 7045 Crank Broke - Rebuild or Swap?
Posted By: AllisHunter
Subject: 7045 Crank Broke - Rebuild or Swap?
Date Posted: 31 Dec 2020 at 6:43pm
| I know this has been discussed many times but wanted any new opinions I could get. The crank in my 7045 is broke. What’s everyone’s thoughts on rebuilding or replacing with another 426 vs a swap of a Cummins or something similar? This is my main tractor and will be for a few years. I want something I can depend on as much as possible. Thanks and happy new year! |
Replies:
Posted By: HD6GTOM
Date Posted: 31 Dec 2020 at 7:33pm
| I'd find a new or good used crank, bearings, gaskets and go with it. |
Posted By: Lonn
Date Posted: 31 Dec 2020 at 8:12pm
|
Had the engine been overhauled before? ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: DSeries4
Date Posted: 31 Dec 2020 at 8:43pm
|
Replace the crank and overhaul while you are at it. Then you know what you have. Buying a used engine Allis or other brand is a crap shoot. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '61 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Posted By: AllisHunter
Date Posted: 31 Dec 2020 at 9:05pm
| I don’t know forsure. I just bought the tractor with the understanding something was off with the motor. I knew it was a gamble but I didn’t plan on the crank because it seemed to be running well. The way the oil pan gasket was on, I think it’s been off before. The crank broke in front of the number 1 cylinder which seems kinda strange. |
Posted By: Lonn
Date Posted: 31 Dec 2020 at 9:32pm
|
Is the crank damper pulley real bad? I remember a 7080 that did that exact thing in the Allis shop the few years I worked there back in the early to mid 1990's. New crank and bearings and what not and it went on it's way. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: AllisHunter
Date Posted: 31 Dec 2020 at 10:20pm
| I don’t know honestly. My friend that’s helping me with it said he was really surprised how it was broke and wasn’t sure why it would do that. |
Posted By: bigal121892
Date Posted: 01 Jan 2021 at 8:11am
| Might have been overhauled and the block wasn't line bored, therefore the crank wasn't in there square. |
Posted By: PaulB
Date Posted: 01 Jan 2021 at 3:29pm
|
A 5.9 cummings would be cheap compared to rebuilding the 426 and it would also have more power and be rock solid dependable. However fixing the Allis motor would retain it's value. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: DrAllis
Date Posted: 01 Jan 2021 at 4:04pm
| Give me a price for a 5.9 Cummins that will make 170 HP at the flywheel. New or used or whatever. |
Posted By: DougG
Date Posted: 01 Jan 2021 at 4:09pm
| Good call, as it would not be price comparison in no way - |
Posted By: DrAllis
Date Posted: 01 Jan 2021 at 4:26pm
| I've looked around a little and cannot seem to find anything OF THAT HP RATING for less than $4500 used. Then you have the custom backplate and flywheel/torque limiter connection and keep adding on from there. |
Posted By: tbran
Date Posted: 01 Jan 2021 at 5:05pm
|
unless one is doing the labor and not figuring and labor cost - I think one will find the labor + adaptor stuff will = the price of that engine... we have done 3 , on deutz and 2 Cummins... unless one has a complete kit - figure 30 hours... min,,, adaptor, flywheel, torque limiter, fuel lines, front motor mounts, rear plate, AC - radiator hook ups , alternator and wiring throttle controls , exhaust system, mating intake from air filter... and probably 10 other things I forgot. I would shop for a salvage 426 form a L or N and swap out the front cover, pulley === probably less hours than a tractor motor. ------------- When told "it's not the money,it's the principle", remember, it's always the money.. |
Posted By: FREEDGUY
Date Posted: 01 Jan 2021 at 5:56pm
Just WHAT makes a crank break ?? the crank in the XT snapped in 2 18 years ago while pulling a 12' disk AFTER pulling a 5/16 moldboard plow (hard)  ?? Thankfully dad had a qualified Allis dealer to make the repair  !!
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Posted By: PaulB
Date Posted: 01 Jan 2021 at 6:03pm
I have one I'd sell for $2500 Drove the truck home then parted it out as the frame was rusted. About 220,000 miles Advertised by Dodge @160 HP a little tuning and 200 isn't a problem.  ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
DrAllis wrote:Posted By: DrAllis
Date Posted: 01 Jan 2021 at 6:05pm
| But, that truck engine doesn't have a variable speed tractor governor?? correct ??? I see it has an air-to-air aftercooler, which wouldn't really allow 200 HP in the tractor chassis without it, maybe not even allow 160 flywheel HP without it ?? |
Posted By: DrAllis
Date Posted: 01 Jan 2021 at 6:20pm
| I've never seen an XT turbo diesel crank break, but my crankshaft grinder is extremely anal about how to actually grind a crankshaft and making the radius grinds perfect. A good deal of crank grinders don't understand that and grind the corners nearly square and then down the road, a crank may break. A good friend of mine, who was an old AC dealer had multiple XT cranks break over the many years he was in business and figured out it was his machinist who was causing the problem. Some crankshafts should NEVER be reground undersized because they have been gotten hot from a bearing burnout. Whenever that happens, the crank is usually junk even tho it may magnaflux OK for cracks. |
Posted By: FREEDGUY
Date Posted: 01 Jan 2021 at 6:36pm
|
Until the crank breaking, that was the first time the engine was opened up since the factory closed it up . Yes, a new crank was installed at the dealers shop back then .
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Posted By: DrAllis
Date Posted: 01 Jan 2021 at 7:12pm
| Then, your failure was due to a bad crank pulley damper or a bad piece of crankshaft steel. Line bore probably wasn't the issue unless the repairman had it line-bored while apart. |
Posted By: pirlbeck
Date Posted: 01 Jan 2021 at 11:44pm
|
Dr Allis is correct about how important the fillet radius is as far as crankshaft strength. When I worked for the Allis dealer many years ago (I started my own shop in 1976) I had a 190XT break a crankshaft within a year or so of rebuilding the engine and having the crankshaft reground. I remember reading in the AC 190XT manual (after the failure) a warning along the lines of " when regrinding the crankshaft, do not decrease the fillet radius or crankshaft breakage can be EXPECTED".
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Posted By: SteveM C/IL
Date Posted: 02 Jan 2021 at 1:32am
| My 8070 manual is very specific about journal fillet radius...even diagrams it for the slow. |
Posted By: pirlbeck
Date Posted: 02 Jan 2021 at 9:20am
It is the radius of the transition area from the crankshaft rod or main bearing journal (bearing surface on he crank) to what would be the vertical or thrust portion of the crankshaft. Here is a link to more info. https://blog.k1technologies.com/what-is-a-narrow-bearing#:~:text=A%20fillet%20is%20a%20radius,is%20connecting%20rod%20bearing%20width" rel="nofollow - https://blog.k1technologies.com/what-is-a-narrow-bearing#:~:text=A%20fillet%20is%20a%20radius,is%20connecting%20rod%20bearing%20width .
|
Posted By: Lonn
Date Posted: 02 Jan 2021 at 11:10am
------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: injpumpEd
Date Posted: 02 Jan 2021 at 11:40am
|
A 5.9L swapped into a 7000 series would likely add value. The VE pump on the Dodge pickup engines do indeed have an excellent variable speed governor. There's a 2-155 White around here locally with a 5.9 swapped into it. It is a 175 flywheel hp industrial engine that is intercooled with jacket water. Driving that tractor, you'd never know someone took a 478 out and put a small 359. The 5.9 Cummins is a great little engine than could lol! That white puts out 175 on the pto too by the way.
To the op, I'd get it apart and see what you need, and then get another 426 to get it back together. The 5.9 swaps are nice, but it's a very expensive route! A 426 is a great engine. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: PaulB
Date Posted: 02 Jan 2021 at 2:28pm
|
The NON aftercooled 5.9s (89-90 and later automatic equipped trucks) were also rated at 160 HP. I have one. Then as EPA demanded the fuel was cut back and timing retarded for truck engines, thus the aftercooler brought them back to 160 rated HP, as this 93 I have available engine is. Now turn the screws and roll the pump towards the head an WaLaa , your back to the 200 HP area. Then the next step is the P7100 pump and 250+ even 300 is doable and they will live, even 400 is possible as a turn the key and it goes (and goes and goes and goes...) engine. Unlike a lot of engines that become a time bomb when turned up. They just take a bit more fuel to do that without affecting durability. Allis Hunter was just asking for opinions on what was possible that would be dependable. Dr. Allis just implied that 5.9 engines were not available at a reasonable price, no dis-respect, but they are out there. You can buy rusted out 1st generation trucks and have a low cost repower, if you choose to go that route. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: BrianC
Date Posted: 02 Jan 2021 at 2:56pm
|
The 7045 crankshaft- is it cast or forged? If cast, is it cast iron or cast steel? |
Posted By: injpumpEd
Date Posted: 02 Jan 2021 at 4:11pm
|
I've never seen a diesel crank that wasn't Forged Steel. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: DrAllis
Date Posted: 02 Jan 2021 at 5:05pm
| Well Paul, I said I'd looked around a little, not a lot. I still maintain the total cost to convert to a 5.9 Cummins could well exceed just fixing the 426. I'm not a Cummins hater, just hate to see people led down a path of "it will only take X amount of dollars" and then get to the end and find it turned out to be quite a bit more than the originally quoted "X". Tbran gave some good advice, as they have actually done a few. Happy New Year. |
Posted By: Lynn Marshall
Date Posted: 02 Jan 2021 at 6:59pm
| Friend of mine has a complete N5 engine for sale. $2500.00. Central Iowa location. |
Posted By: NEVER green
Date Posted: 02 Jan 2021 at 7:04pm
|
I wouldnt drop down in cubes to 360, no way. ------------- 2-8050 1-7080 6080 D-19 modelE & A 7040 R50 |
Posted By: tbran
Date Posted: 02 Jan 2021 at 8:51pm
|
The B Cummins in the Agco / White tractors we sold acted like 400 + cubic inch engines. They were very peppy and even though we complained about our lack of CI compared to competition , we never had a customer complaint. In fact we had community of , uh how shall I say -group that all went to the same church - that wore Green suspenders that 'inherited' a RT150 . They came to me to sell the tractor and I agreed.. the tractor never showed up so I assumed they sold the unit. Then report came that the unit was hooked to a grain cart, then 20 Bush Hog then deep tillage tools.. I ask the neighbors to ask what the deal was.. word came back from the younger ones that on light loads the RT was using 1/2 the fuel, rode better, shifted smother and was faster on the road ,,, so they used the heck out of it. I called the person who had called me first and said yo guys look good that orange tractos - he said "please , sell this tractor" we did and it is still running strong... maybe somethings DO run like Deeres.... remember when we were kids and when we didn't like hearing something we put our hands over our ears and yelled nananannana.. :-) ------------- When told "it's not the money,it's the principle", remember, it's always the money.. |
Posted By: DrAllis
Date Posted: 03 Jan 2021 at 7:14am
| Same could be said for some of the 374 cube Deutz engines with turbo and air-to-air cooler. Bottom end torque was good without a black cloud of smoke like a Mack truck. |