Getting first, second and third every time.

Come to think of it, the truck was also struggling in reverse, which is probably pretty close to 1st in ratio.

It is cold, wet and windy ... the streets are deserted.

What exactly happens when you attempt to pull up the ramp? DOes it bog? Is your foot to the floor and and just wont move? Sounds like something is wrong. Even thought the 351 was not a strong engine, it should have no problem pulling up that boat at the ramp.

Are you sure your trailer axle/s are not falling off the ramp under water? I dont know anything about the propane systems, but soemthing is definitly not right.

not motor....trans......check it out.

I have been on the Ford forums and one thing that may explain it is that the LPG we get here used to be all propane but is now a mix of butane and propane. As there is no Australian standard, it varies from supplier to supplier and from time to time. A few of the blower guys have learned the hard way. Maybe I am getting bad fuel.

As it is Easter weekend and there are no workshops open, I think I will drive around, empty the tanks and try a different fuel supplier. It is the cheapest simplest and only option at this stage.

Thunder, as you press the accelerator the revs rise normally to a point and then go no more regardless of how far I push the accelerator. It is as if I am pushing against a wall and have 100% traction. There doesn't seem to be a hesitation or a flat spot as such. If it was a manual, I would just slip the clutch some more, but being an auto it just doesn't go.

The ramp is one of the steepest I have seen, but a Range Rover will do it and a 6 Cylinder 1956 Chev that is pretty well worn will do it. Admittedly the Rangie uses low range and the Chev has a very low first gear. It was high tide, so the trailer was well on the ramp. It also had trouble in reverse pushing the boat up a steep driveway so I think we can eliminate the off the ramp theory.

Tblrklakemo, I went to an automatic transmission specialist and they said to look at the engine. It is not often a workshop doesn't want your money and sends you away. Having said that I think there may be some value in a higher stall converter.

Does anyone know if high stall converters work in towing situations?

The higher the stall the more heat the transmission creates. Then cooling becomes an issue.

Cooling is an issue at the moment but we can add more coolers, is it common for those towing to use higher stall converters?

I wouldnt think a higher stall speed converter is the answer. It sounds to me like the engine may be down on power.

Another option to look into is adding a transfer case from a 4x4 truck. At the ramp you can shift it into low, and then have a really low gear to pull up the ramp. Shouldnt be too hard to rig, since you wouldnt have to add the shafts and hardware to the front axle. Just transfer case, driveshaft, and linkage.

Like I said, sounds like a weak engine and not low enough gearing.

Did a compression test, was great.

Played around with timing, couldn't get it better

Beginning to agree with Mild Thunder. Probably just need lower gearing, need to look into the transfer case.

Just thought I would update this.

Quite a while ago we put in a C6 and 4wd transfer case to get low range gearing. The FMX didn't last long at all and was most unsuitable to the weight of the truck.

Now the truck has no issue with bogging down, just no traction. Changed tyres and dropped tyre pressures which helped.

Next step is to soften the rear suspension as there are a lot of leaves and/or add some weight over the back wheels. The truck has no overhang at all at the rear and is much higher at the rear than the lowered front. This may have been great in its previous life when it had to lift the front of vehicles it was towing, but trailers are not providing enough downforce on the wheels.