Deutz 6806 tractor

Hi everyone,
This my first post...so be easy on me lol,I have a 1978 D6806 Deutz thay my dad bought new...my question is..it has always had 20w non detergent motor oil since new..i would really like to switch to shell rottela 15w40 (I know..i know) but any person I talked to about it..has a different answer(no don't do it,it's ok if you take off the pan..valve cover..etc) its getting hard to find NT oil here... at best I would like to put 40w non detergent oil..but can't find any..this tractor (to me)always ran a little hot in summer when I used the bush hog..i think it needs a higher vis for summer..shell 15w40 would be ideal but I am afraid if I make the change it will plug the oil pump,spin a bearing..so I don't know what to do. What do you think I should do?
P.S. I also have a 1966 MF 135 with the gas cont engine z145..we also bought new...that I now use 10w40 penzoil that I switched 20 years ago from nt oil..with no problem..just did a lot of oil changes..for first year. Deutz has 4500 hrs MF 135 has 3500 hrs.Dad only changed oil every 2 years in both lol...so you can imagine about what shape they are in...but both run very well. Thank you for reading my post.
Best regards, Keith

Hi Keith,

Tractor doesn't care what oil you put in it. Just grab one.

Oh, and ya don't have to change oil every time the sun goes down either. :>)

Allan

How much sludge/residue can you see on the dipstick, inside filler cap, pcv if it has one? Have you ever had valve cover off, if so what kind of buildup was present? I ask to give you an idea of how many oil changes you might be prepared for. I'd go to 15w40 knowing I will do several oil/filter changes soon after.

I had the same problem with an older tractor I added a qt of diesel to the oil ran it about 1 hr no load. Dropped that oil, then added shell 15 w 40. I kept close eye on oil pressure and temp listened to engine all was well, changed oil after about 50 hrs all is still ok

Doesn't seem to be much sludge in the pan. I plan on taking it off completely to change gasket...then the valve cover..to be certain...from just putting my finger in the oil pan plug hole...it seems fine. I don't know why he ran non detergent..because nowhere in the manual says what type oil really to use. It says deutz MK oil or equivalent...what the heck is MK oil?

I was gonna try some sea foam in the oil before I changed it...but I chickened out. lol

Dang german tractors anyway...lol

If you are going to drop the pan and clean everything up, I see no problem switching to detergent oil. Might do a couple extra filter changes if it starts looking dirty. Otherwise just do it and change it as you normally would.

Those horror stories about clogging pick up screens, I doubt that it was really caused by switching oils. An engine that is that seriously sludged up was already on it's last leg anyway. That sludge comes down from leaking rings. A healthy engine will not be making sludge.

Good choice on the truck oil. Diesel/truck oils still have the zinc additive, something flat tappet cam engines need. Modern automotive oils no longer have zinc.