HD11 EP

Maybe clutch pressure is low on 1st gear pack(s). A trans rebuild may be needed, but often, the cost of the parts needed is not excessive, and if you do it yourself, it wont cost a lot. As with all the post second world war HD series crawlers (HD5 to HD21), they are very good tractors. 

Still a very good "farm duty" machine, and can be picked up much cheaper than comparable D6C.  I've worked on quite a few HD11s, parts are getting harder to find, but I haven't been stumped yet, other than trying to find a reversible fan.  Good used undercarriage can still be found, just looked at a couple of good used track groups (rails and pads) for HD11E last month, also looked at an 11-B which had been converted to CAT tracks- looked real good.

Undercarriage can still be found, you'd have to figure on 5K for rails and sprockets, though. (new sprocket rings are around 1K, or could probably get adapter ring and segments for a bit more, between 3-4K for good used rails, shipping in)

Some people don't like the AC final drive because the bearings need to be re-set, but the best feature is that they are easy to work on, and quite affordable to rebuild, compared to the CAT design, which requires heavy tools.  I was just talking to an HD11 owner the other day, and he said "that Fiat is a poor man's cat".  He had broken a final drive shaft, pulled the track frames off out in the bush, and rebuilt the final drives for less than $5000 (this is a few years ago) doing all the work himself.  Several years later, he had final drive problems with his D7F, and of course didn't have the proper tools.  He had the dealer come out, and it cost $41000.  "The sad part is", he said, "I'm not sure I get any more work done in a day than I did with the 11-B, and I feel like I'm sittin' in a damn tub."  He had a big bar welded on the dozer to get up high on trees, and a bit to split stumps, his brother had a D6C, but it wouldn't touch it.  D6 might have been the earlier low horse model, though, and did have wider track shoes- the only thing that Cat had better was the 3 speed transmission, which guys really liked.  The Allis crawler tractors were as good as any on the market in the 70s, but had lost much of their market share by that time, and the FIAT merger did nothing to improve the situation.

I don't know of anyone who has owned an HD-11 and didn't feel it was an excellent machine. I have two, would like to have an HD-11EP, myself. Mine are both HD-11S Tractors. I have a complete undercarriage off an HD-11AG (10,000+ serial number) that was being rebuilt until the parts to complete it had been misplaced. The rails are 80-90% with pins and bushings having just been turned, grousers are good, Idlers are very good with rock guards, Rollers are all new (all single flange, unfortunately), Sprocket rims are new. I had a buyer for the rails and rollers, but haven't heard from Him in some time! I am in San Diego, also have a place in AZ and would be willing to meet somewhere in the area.

Access to a donar tractor would be the ticket. The Allis equivilent of D7 17A is HD16, not HD11. If your grandpa could honestly say his D7 would walk circles around an HD16, that would completely contradictory to all of the comments I`ve heard from tractor loggers and mountain tractor men with 50 years plus experience running them

I am interested in an HD11B for sale near me. Where can I find year and serial number information and when the design improvments took effect? Unfortunatly this machine does not run so I can't tell if the steering clutches work. What should I pay for a machine that does not run?

The Fiat Allis Service Publications Index shows all the changes on the HD11 page George. It gives the serial # range for applicable parts catalogs for each component group. Where different parts books apply for any given component, a change was made. Very useful little book

Google "Allis Chalmers Tractors and Crawlers" choose Terry Dean - Google Books Page 148 has info about the HD11 I was unable to print the pages if someone knows how, please tell me. Will someone comment on the torque converter drive vs the 6 speed My HD7G torque converter has remained a project I might get to someday while I use and repair my HD6G's. Do the direct drive HD11's have dry clutches and wet clutches? Can I tell by the serial number?

17A D7 is on par with a HD16D/DC. Uncle had a 16DC on heavy native timber logging and was working alongside a turbocharged 17A belonging to a sub contractor. Both machines were new and both performed well. But the AC performed far better for pulling and winching work due to the torque converter drive. This was in the early 60s.
From what ive been told the 11EC performed very well in logging and ripping and pushing work. Its downfall was almost too much power from the 4.6 -1 torque converter combined with the slower 3 spd manuel box. It produced too much torque at the sprocket and they broke final drive gears and the ends off the live axles.
As with all machines, the man in the seat plays a big part in this. Only way to 'focus there train of thought' here is to make them help fix it when they break it
sounds like your granpa should have got a 11B/E if he wasn't conversant with torque converter drive. Both types of drive have advantages, depends on the work your doing. A HD11B @ 99hp would be most comparable to a D6B or 9U @ 93hp

Very nice old photo.  Looks like '61 or '62- dry steering clutches, and the oil bath cleaner by the looks of it...

Craigslist in Springfield Mo has several HD11s on it. 2 with rippers...