compression check

my compression test on my jd 3020 gasser showed the following 130/135 oiled;120/140oiled;135/145oiled;120/125oiled.dealer says 6-8000.00 for overhaul. how needs to be done. what does a overhaul get you. what do they replace and repair? what is a good compression for this tractor. ps what year is it. serial# T111R 125392R. I thank you all who respond.

If it's doing the job you require not using excessive oil Oil analyis shows no undue wear , lab tested, just run and enjoy it!!

Unless there is some other problem, why the overhaul?

120 to 135 is not that far out of specs. If it is leaking,running bad, using excessive oil that is different.

Surely I mis-read that...6-8 THOUSAND...?? You can buy a LOT of oil for that amount if oil consumption is your main worry.

JMHO

Rick

That sounds pretty high....you oughta "shop around".. Now, if it's totally shot, maybe, but you don't describe it as that. You don't need someone with a degree from MIT working in a NASA cleanroom to overhaul a 3020 gasser.

I've seen gas engines run with compression in the 90 psi range so where your at between 120 and 145 I'd run it just like it is.

That said while others may think the dealers price sounds high they aren't comparing apples to apples. When I estimate a price on a rebuild of pretty much any engine nowdays the standard formula, that works 9 times out of 10, is $1500 to $2000 per cylinder. Those figures include parts, machine shop charges, labor for removing, and rebuilding the engine as well as putting it all back together after the rebuild. Then there also has to be a bit figured in for unexpected expenses like replacing a cracked head, sleeving or replacing a block that has already been bored to the max oversize, etc. etc. Basically you have to give a customer a figure that includes any problems that you forsee that you might run into so they go into the rebuild with open eyes. Think about it this way, if they told you it was going to be $4000 to rebuild, you agreed, so they started the job. After things were torn down and taken to the machine shop, who bored the block, polished/ground the crank, etc, etc. Then they started on the head only to find it was unusable and a replacement was $2000 and two weeks out. Put yourself in the dealerships place when they have to call a customer and say that the job they gave a price on was going to cost half again as much, and that regardless of what you wanted to do you still owed $2000 worth of shop time and machine shop charges so far.

I got put into that position by a amchine shop last year when the told me they had a head already complete for a customer, and were working on everyting else. At the lat minute they called and said they had NOT done the head, that it was cracked and I needed to find another one. Calling the customer and telling him that he needed to spend another $2000 plus to buy a head that I had already told him was complete didn't go over too well. Fortunately the guy was very understanding, given the circumstances, and didn't blame me for the problem...but things could have gone very differently and I could have got stuck with the bill for what had been done so far by the machine shop, as well as a farely good amount of labor and expenses I had invested just getting the thing pulled and to the point it was at. In my case the machine, a D6 CAT dozer, was sitting on the customers yard, but in the case of a dealership your tractor would either be taking up a bay for x amount of time which also costs them other work that could be there in it's place.

If you do the work yourself you can probably beat the dealership price by 1/2 to possibly 2/3, or call an independent who could probably also shave some off of the dealership price.

Either way your going to save a little money, but given what you say I'd save it all and run the thing just like it is unless it's slobbering oil uncontrollably, or knocking, or exhibiting any other signs that inducate it's getting ready to throw a rod, etc and boost the cost of a rebuild even higher.

So what is wrong with the tractor? Obviously not the compression. I've seen rebuilds barely get 140#. $8000 for a valve job???... and what else will he not do cause it doesn't need it. You need an honest mechanic, not a crooked service manager, but a kid that plays with engines. There is a gear head in his teen's to his 80's in every town that would be happy to look at it, and give you an honest opinion- or put in a tune up kit- for a 6 pack and a pizza.