PT 425 - repower options (Kohler 25hp)

[Modrob]

I did call Tazewell yesterday and talked with Terry. He sent me straight out to pull the low side valve cover off, and look for a bent pushrod. Sure enough, as soon as I pulled the cover, I saw the Exhaust rocker cocked nearly sideways, and its pushrod bent. Called Terry back and he laughed, said it was as he suspected from all I had told him. Also this was a fairly common thing on these for some reason, and he had a couple on his desk at the moment! Replace the rod and should be good to go again. (Of course I’ll drain/change all the oil and filter) I did find some junk/buildup on the head outer surface and from watching more videos I’m thinking that oil contamination affected the lifter, causing it to become more solid-like and causing the bend. I also asked about pulling the head to get to the lifter and clean it up but he said I shouldn’t have to go through all that. Ive seen some videos too where the lifter was pulled from the top with a tool…hmmmm….and seen warnings against using a magnet. (??) I’ve ordered a set of 4 rods…

 

[MossRoad]

See this post from Monday in your other thread...

PT425 towing mode??

Carb cleaner is not a bad idea to give it the extra margin of help to get re-started. You might have a gummed up carb anyway. When I had trouble with my Terramite, I also replaced the spark plugs to be sure they weren't the source of the problem and were clean. And now that I think about...

www.tractorbynet.com

 

[Modrob]

That 1950 IH sounds like fun! Where are you located? Hills? Mountains?

25HP diesels aren't exactly common, or cheap, but I think that it would make for an interesting tractor. But budgets, health, age, etc., do have a material impact on what is reasonable, in contrast to what might be possible...

All the best, Peter

Yes, the Crawler has been fun so far, with a steep learning curve on handling the blade. (I’m slowly getting better at it but still a ways to go) And learning its systems—one, I’m in a different world with stuff so heavy one needs machinery to lift/maneuver…
Yep, I’m in the “hills…mountains” of WV. Right alongside the Allegheny Trail of Peters Mountain. Rough weather here at times and the WINDS—downright terrible at times!

 

[MossRoad]

We'd love to see some pics of the crawler.

 

[Modrob]

I have done a couple of engine swaps on PTs. It is pretty easy. Power trac can set you up with any parts you may need to adapt a new engine. Word of warning when installing the 90 degree oil drain elbow: do not overtighten or you will crack the block.

The following Kohler engine spec numbers will work. The HP ratings are per Kohler:
CH 730-3207 (23.5 hp) this one is in a 2422 with pumps on both sides of the engine
CH 730-3208 (23.5 hp)
CH 740-3363 (25 hp)
CH 730-3004 (23.5 hp) this is an old spec number but can still be used as a reference

Another spec number that may work, but I have not used is CH 750-3006 (30 hp)

When I called Kohler directly a few years ago, one of their service reps went through and identified a number of spec numbers that should work. He said they change some of the internals to get the different hp ratings, but the rest of the engine is a drop-in replacement.

Hope this helps

Thanks much for that great info. I’ll file it with my other notes, and hopefully I won’t have to use it soon…

 

[Modrob]

We'd love to see some pics of the crawler.

I love it. It’s a bit over my head but I’m learning more about it as I find books/manuals. All of the running gear was rebuilt and it’s really in great shape. My neighbor/friend works for a local mom-and-pop equipment place and does most of their rebuilds on dozers and such. He did the finishing touches on it before he delivered it to me. (His boss/shop owner owned the Crawler, passed down from his late daddy, who along with dad’s brother had done all the rebuild a few years back)

 

[m5040]

I love it. It’s a bit over my head but I’m learning more about it as I find books/manuals. All of the running gear was rebuilt and it’s really in great shape. My neighbor/friend works for a local mom-and-pop equipment place and does most of their rebuilds on dozers and such. He did the finishing touches on it before he delivered it to me. (His boss/shop owner owned the Crawler, passed down from his late daddy, who along with dad’s brother had done all the rebuild a few years back)

My back hurts by just looking at it.

 

[MossRoad]

I love it. It’s a bit over my head but I’m learning more about it as I find books/manuals. All of the running gear was rebuilt and it’s really in great shape. My neighbor/friend works for a local mom-and-pop equipment place and does most of their rebuilds on dozers and such. He did the finishing touches on it before he delivered it to me. (His boss/shop owner owned the Crawler, passed down from his late daddy, who along with dad’s brother had done all the rebuild a few years back)

Love the seat... throne of power!

Sometimes I pretend my little PT425 is such a beast!

 

[2manyrocks]

Comparatively speaking, 25hp in a 4wd PT425 is a beast relative to the 1970s garden tractors that were 2wd, 16hp single cylinder and rarely had hydraulic lift.

 

[scotts562]

Glad you found the problem. With the benefit of hindsight, were there any warning signs prior to failure (strange noise, smoke, power loss etc.) or did it give out without warning?

FWIW, my brother has advised me to only run the Kohler brand engine oil in Kohler engines. The place he works has hundreds of kohler engines in various small equipment. Over the years they have noticed the ones using kolher brand oil keep plugging away while the ones receiving other brands of oil fail prematurely. They can't figure out why the engine oil brand would make such a difference, but that is the trend they see.