Where is the 7788 Tractor

[Bermuda_Ken]

According to IH, they made the following.....

7388............3 made

7588..............2 made

7788...............3 made

Supposedly enough spare parts exist to build 1 or 2 more.....

 

[dale560]

5 hours ago, SDman said:

Back to my original question from years ago...after that auction in Canada happened, it became apparent that there were no less than three 7788s and 7388s that were built and sold to the public. Has there been any other 7588s that have been found other than the one that lived in Iowa for years that is now owned by the Swensons in ND?

I knew a guy that worked for Grouser dozers up in West Fargo, ND, years ago that had pictures of a 7588 when they were new. Grouser actually got ahold of it to see about making a dozer & mounts to work on it. I don't recall that any of the pictures showed an actual finished product of a dozer mounted to the 7588, but they did have the actual tractor there.

The guy that owned grouser was a brother and son to the family that owned the Ih dealership here in our town. The Dad and the other brother that farmed were well respected in the IH world with their long time custom combining operation that ran IH from the 151 days up through the 1688s. They had enough pull with Steiger and IH to get access to new stuff. These guys were running a prototype rotary in the development days way back when.

[SDman]

On 2/10/2025 at 9:42 PM, Dirt_Floor_Poor said:

So the 7788 was detuned some compared to a 4786? Was there a lot of problems with the DVT800 when set at 350 hp? My dad borrowed our neighbors 4586 when it was new. He was impressed, but we didn’t have anything like that back then. He said it ran off with the 32’ disk. Our neighbors didn’t keep any tractors long enough to wear them out back then. I know they had some engine problems with their 4786 when it was new. It was eventually traded on a new 975 Versatile. 

The 73/75/7788s were all slowed down 200 engine RPM for rated speed as compared to the 43/45/4786s they were supposed to replace.

If you look at IH tractor ag engines in general, IH slowed down their engines at that time in other places, too. When you look at the 66 series IHs, when IH bumped up the HP in the latter half of 66 series production, the rated speed of just about all the 66 series went from 2400 RPM to 2600RPM. When the 86 series came out, everything smaller than a 1486 was slowed down to 2400 RPM. When the 50 series came out in 1981, all of them ran at 2400RPM. Not sure if that was in response to the cavitation issues the 400 series were dealing with, overall longer engine life due to slower engine speed, or something else.

The 75/7788s were also detuned 20 HP from the 45/4786s. Don't know that I would say that the 4786 had any poorer reputation at the higher HP than the 4586 did at 300HP. By the time I dealt with the DV-800s in IH 4wds, they were all getting tired from what I would consider normal use. The lack of engine air filter capacity has been mentioned on this forum over the years....that must be why just about all of the IH 4wds of that vintage I was around had a Turbo II precleaner sticking out of the hood. 

Speaking about HP, I've got an interesting story about Jay Graber's 7788 when it was new. The guy that predelivered it back in 1981-82 is a service manager for a CaseIH dealership a couple hours east of here. According to him, one of the first complaints from the guy who got it new was that it was low on HP. He went out to look the machine over, first thing he noticed was that high idle was a good 100RPM below spec. He got to looking at all the linkage from the throttle lever to the injection pump, and found everything was adjusted to its limit to try to get the high idle speed up to spec. His local IH rep. had him talk to someone in IH's engineering/product behavior group, and that guy knew all about it. They had identified it as a problem to be dealt with when regular production of those tractors was to begin. At the time, the guy's only answer for him was to grind the slot on the upper end of the throttle lever about a 1/2" further to allow for more travel of the throttle lever. When he saw this tractor at RPRU 2014 in Huron, he knew this was the tractor he worked on when it was new just by the cut in in the console that he had made 30 years previously. I know the son of the guy that bought that 7788 new...I know he said they were disappointed in the HP of the 7788, but he never went in depth on the subject.

[Drysleeves]

55 minutes ago, SDman said:

The 73/75/7788s were all slowed down 200 engine RPM for rated speed as compared to the 43/45/4786s they were supposed to replace.

If you look at IH tractor ag engines in general, IH slowed down their engines at that time in other places, too. When you look at the 66 series IHs, when IH bumped up the HP in the latter half of 66 series production, the rated speed of just about all the 66 series went from 2400 RPM to 2600RPM. When the 86 series came out, everything smaller than a 1486 was slowed down to 2400 RPM. When the 50 series came out in 1981, all of them ran at 2400RPM. Not sure if that was in response to the cavitation issues the 400 series were dealing with, overall longer engine life due to slower engine speed, or something else.

The 75/7788s were also detuned 20 HP from the 45/4786s. Don't know that I would say that the 4786 had any poorer reputation at the higher HP than the 4586 did at 300HP. By the time I dealt with the DV-800s in IH 4wds, they were all getting tired from what I would consider normal use. The lack of engine air filter capacity has been mentioned on this forum over the years....that must be why just about all of the IH 4wds of that vintage I was around had a Turbo II precleaner sticking out of the hood. 

Speaking about HP, I've got an interesting story about Jay Graber's 7788 when it was new. The guy that predelivered it back in 1981-82 is a service manager for a CaseIH dealership a couple hours east of here. According to him, one of the first complaints from the guy who got it new was that it was low on HP. He went out to look the machine over, first thing he noticed was that high idle was a good 100RPM below spec. He got to looking at all the linkage from the throttle lever to the injection pump, and found everything was adjusted to its limit to try to get the high idle speed up to spec. His local IH rep. had him talk to someone in IH's engineering/product behavior group, and that guy knew all about it. They had identified it as a problem to be dealt with when regular production of those tractors was to begin. At the time, the guy's only answer for him was to grind the slot on the upper end of the throttle lever about a 1/2" further to allow for more travel of the throttle lever. When he saw this tractor at RPRU 2014 in Huron, he knew this was the tractor he worked on when it was new just by the cut in in the console that he had made 30 years previously. I know the son of the guy that bought that 7788 new...I know he said they were disappointed in the HP of the 7788, but he never went in depth on the subject.

Great story.