Considering replacing the Vanguard engine on your tractor?
Recently replaced a 1996 vintage 16 Vanguard with a 2020 18 Vanguard on a 4016. This was a learning experience for me and I will share this with you.
These engines are getting tired as the hour meters continue to build more time.
For ease of description, I'm going to call the Vanguard flywheel and cooling fan changes phase 1, phase 2 and phase 3. As the flywheel is where the hydraulic pump on Ingersoll GTs, this is important.
Phase 1, Vanguards produced in the 90s:
These engines have a cast iron flywheel with the cooling fins as part of the casting and usually painted black. The pump drive coupling bolts directly onto the flywheel with two bolts and has a centering pin or ball that correctly centers the pump shaft/coupling. The debris screen is captive on the pump shaft between the pump and the coupling and is held in place with 4 standoffs that are threaded into the flywheel. As Vanguards are primarily metric, one thread on the standoffs is metric, the other end is SAE or American thread. The depth of the blower housing is commensurate with all. I'm going to call this the 'shallow blower housing'. The flywheels have a cast aluminum starter ring gear riveted to them and require a specific starter motor which has a black nylon gear on it.
More to come!
Moving onto phase 2.
The cast iron finned flywheel with a riveted diecast ring gear has been discontinued and replaced with a smooth flat faced one with a bolt on plastic cooling fan and a steel ring gear. The starter motor has been changed to one with a steel gear mounted onto a shaft that has the spiral gear machined onto it. The blower housing is the same one used on phase 1. The steel flywheel ring gear is not a replaceable part, a new flywheel is the only option.
The mounting of the plastic cooling fan is where the fun starts as it uses two of the four bolt holes on the flywheel with a support ring to secure the fan to the flywheel. This prevents the pump coupling from having a flat firm surface to mount onto. Bear in mind that there is a pilot pin that presses into the pump coupling, the pin of which aligns into the hole in the center of the crankshaft. As the pump doesn't have a mounting bracket, its alignment relies on the pilot pin in the coupling. There is an anti torque arm bolted to the pump, the toe of which rests on a shock mount.
Unfortunately, the Ingersoll parts manual for Vanguard powered 3000 & 4000 tractors which is 8-3112 with the latest update being November 1992, so we don't have info on the installation of the plastic cooling fan Vanguards. I see where some folks are having to re-powering the newer black frame models. There is no doubt that Onans were more durable than Vanguards, but Onans like any other engine also have some weak points.