Rebuild time?

[Kodiak45]

How do you tell when it's time to rebuild? I'm going to start tearing down my 72 jd 4230 in the next few months for paint and I thought I would ask if it's even worth considering doing any preventative engine work when it's not smoking blue or white and very little black. It's got 5500 hours on it and no leaks that I can see. Is there any reason to get into gaskets or have anything checked like valves and so forth...? I only plan on taking the sheet metal off and painting. I assume the answer is no, but I dont like having regrets. I'm not aware of any prior engine work other than some fuel work like an injector or so

 

[jeff9366]

If its gas, do a compression check.

 

[boomer1025]

Wouldn't hurt to adjust the valves with 5500 hrs

 

[wmonroe]

I would adjust the valves and if the injectors are original have them rebuilt or replaced, but if it is holding good oil pressure and shows no sign of problems I wouldn't open the engine up.

 

[Kodiak45]

I'm so glad I asked so I can get prepared. Can the injectors be rebuilt? Anybody know if valve adjustment is something a novice shade tree mechanic can do on this tractor?

 

[jenkinsph]

I would adjust the valves and if the injectors are original have them rebuilt or replaced, but if it is holding good oil pressure and shows no sign of problems I wouldn't open the engine up.

I agree with this^^^^
Might also consider sending in an oil sample to get it an analysis.

You should be able to adjust the valve clearance with a feeler gauge and shop tools. I know nothing about it though.

 

[Kodiak45]

Another good call on the oil sample. Who do you normally use, Ive never done that before.

 

[jenkinsph]

Last time I had to send in samples I sent them to Caterpillar, haven't sent any on the Deere squipment I have now. You can find testing labs easily on the net. I think Deere does testing as well.

The good thing is that the engine is easy to rebuild if it is needed in the future. Repainting after a rebuild would be simple too. If you want to know how good the motor is most large dealerships can test it on a dyno and monitor it. Personally if it runs well and seems strong enough I would leave it alone. Better to take the time to do a good paint job take all the covers off you need to paint it properly and check for any loose bolts or problems. Shifter boots, battery boxes rusted out, belts, hoses, cracked rubber lines (including the small return lines between injectors if it has them) and fix any thing you can that leaks. I would clean it after fixing everything that leaked and run it long enough to be sure you fixed all the problems. Make sure the air conditioner is clean too. Then change the hydraulic fluid. If it worked without problems for two weeks I would paint it.

 

[oldpilgrim]

If it's not smoking, starts like always, makes no unusual noises, has normal oil pressure, I'd leave it alone.

 

[Billrog]

Maybe do the valves but I wouldn't do anything else if it's running good. I replaced the injectors on a backhoe once with 12000 hrs. and it didn't make a bit of dif. Sold the last BH with 15,000 hrs. and nothing but oil changes from day 1.

 

[big bubba]

does the engine or trans. have any leaks? another sign of wear. if not, as previous posters mentioned, i'd leave alone. good call on injector rebuild/replace. does it have glow plugs? if so, might be worth a check. as far as valve adj, good advice to adjust. if you've never done it on gas/diesel engines, i'd recommend getting someone over on site who knows how. & call the dealer on the intake/exhaust clearances, & whether done cold, warm, or hot. & of course replace valve cover gasket when completed. great project! like those old school machines. also great advice by jenkinsph

 

[Kodiak45]

no leaks and no glow plugs. I'll definitely get some help on the valves as I don't like to learn the hard way. Thanks for the words of encouragement. I'm pumped about the tractor, now I just need to get some bigger implements to actually use with it. I look forward to what he oil analysis tells me.

 

[big bubba]

absolutely on the right track, wise move to post on forum. hey, why not some pics of finished project? we want to see results of gettin' down & dirty where most operators would just let their older equip be. good job

 

[wmonroe]

Another good call on the oil sample. Who do you normally use, Ive never done that before.

I've used "blackstone labs" quite a few times, if you go to their website they will send you the test kits for free and I think the analysis costs about $20.

 

[Kodiak45]

Blackstone is who I am going to use. I requested a few kits from them and I've already got the 4230 sample ready to go. I look forward to getting the results.