Power Tilt/Trim question

[Justinde]

Hi all- again;-)

My PTT pump is pumping ( whirring noise when switch toggled), but it does not seem to be pumping the hydraulic. I took the top of the unit off, and the bottom of the shaft doesn't seem to have a keyway or any way to slot into the lower unit. When we are bleeding the unit, it does not seem to be moving any oil, we put our thumbs over the oil filler hole, and it does not feel like anything is going on. We ran the pump for about 2 minutes and there was no change in the sound from the unit.

Any ideas what to do next? I didn't hit anything- I just needed to bleed the unit, it was working just fine until then.

If you need a pic or more info, let me know;-) Its a 1988 Force 125.

 

[Jiggz]

Re: Power Tilt/Trim question

The main shaft of the motor is not keyed to the valve body or pump, instead it is fitted with a slotted tip on the shaft and on the oil pump gear, well at least that's what mine looks like. The oil fill hole doesn't do anything except to provide access to fill the unit with hyd oil. You need to make sure the unit is filled with hyd oil and properly bled.

Raise the motor using the PTT and if the unit will not rise at all, try assisting it by hand raising the motor. Watch the trim piston if it will rise indicating hyd oil pressure is pushing against it. If it doesn't rise, it means the pump is not pumping oil at all. If it rises it tells you the oil pump is pumping and the reason it would not rise by itself is it could be the shuttle valves are leaking very badly.If the trim piston would not rise at all it tells you the pump is not pumping hence the oil gear pump could be seriously damaged.

If you decided to troubleshoot the valve body due to leaky shuttle valves, after disconnecting all 4 lines and dismounting it from the electric pump body, there should no need to further disassemble the pump body except to remove the shuttle valves for inspection.

Post a pic of your PTT to make sure we are talking on the same page.

 

[jerryjerry05]

Re: Power Tilt/Trim question

The 88 only used the Prestolite motor/pump.
Did you force it when you put it back together.
It should have slid right back in and screwed right back down.
Any force and you could have pushed the connector and screwed up the connector.
Take it back apart.Take the pump off the base and inspect the slot for the armature shaft.
Then put it back together and fill it with oil 30w.
The filling should be done while in the down position.

 

[Big Fish Billy]

Re: Power Tilt/Trim question

My 1997 Force 40 hp has an "H" type shaft connector between the motor and unit below. When I took my motor off to clean it, and then put it back, that little part had slipped out of position and I had the same symptoms as you, I didn't realize that part had moved. It is part number 7 in the link below. Not the best setup but now that you know it's there you can get it back in place.

Mercury, Mercruiser, Force, etc. - POWER TRIM ASSEMBLY - 40/50 H.P.

Bill

 

[Justinde]

Re: Power Tilt/Trim question

Silly Question before I take it apart and re-check the connection- when I prime it in the down position, I want to try and lift the motor yes? Do I release the engine all the way down with the trailer jacked up, then pump it up, or is part way down ok??

 

[RRitt]

Re: Power Tilt/Trim question

the VB portion is difficult to seat onto armature shaft while system is mounted on boat. IMO, you should take pump and motor off boat. fit them together and install the pump as an assembled unit.

leave two tubes connected to engine and two tubes connected to VB when removing and installing the pump. Install pump only after VB and motorare properly seated and tightened. this will eliminate your struggles to line up tubes and avoid cross threading.

on 1988 remove the studs and tap the hole to be fully threaded. cut slot on end of stud. using screwdriver, tighten stud through clamp and into mounting nut. This will eliminate having to take tighten two lower nuts 12th turn at a time.

 

[Justinde]

Re: Power Tilt/Trim question

Thanks RRitt, Happy New Year;-)

In Australia, a VB is a Victorian Bitter Beer....... so, before I remove the beer from my boat, what exactly is a VB????

 

[RRitt]

Re: Power Tilt/Trim question

Thanks RRitt, Happy New Year;-)

In Australia, a VB is a Victorian Bitter Beer....... so, before I remove the beer from my boat, what exactly is a VB????

When talking Force, I always try to refer a trim motor and a valve body. When you put the two together then I refer to it as a pump assembly. It seems to be the most agreeable wording with the parts diagrams.

put the trim motor in a bench vice upside down. make sure oring is seated fully down against VB flange. drop VB onto motor. spin VB until it falls into gear. holding it down, keep spinning until the side ports face mounting bracket. install and tighten four screws. finger tighten two tubes going to upper ports on cylinders. tilt port is furthest back and trim tube is closer to middle. take to boat and finger tighten remaining tube nuts. bolt motor onto boat. finish tightening tube nuts. fill reservoir until fluid runs out of hole. run up and down several times. does not need priming or bleeding.

 

[Jiggz]

Re: Power Tilt/Trim question

Oh yes, love those Victoria Bitter! Anyways, RRitt is referring to the Valve Body (VB). Happy New Year.

 

[Justinde]

Re: Power Tilt/Trim question

HI All

I am trying to not take the pump unit off- and spent about 10 minutes on her. I can locate the keyway easily with the electric motor removed completely from the upper body, but as soon as I put the body on the electric motor, it sits up and won't engage. If I manage to keep it in position and tighten the nuts, will it set in and re-engage- or am I wasting my time and have to remove the PTT from the boat at a poofteenth per turn per bolt for 20 years?

 

[Justinde]

Re: Power Tilt/Trim question

Update: I can locate the keyway as above, locked it down, ran the pump for a period of a few seconds at a time, it lifted the engine and had that nice whirring sound- then it seemed to disengage again. I have done this for a few hours now, so, again, do I need to tak the unit off for sure or if I persevere will I get a result??

 

[jerryjerry05]

Re: Power Tilt/Trim question

Hey RRitt how about a pic of the( on 1988 remove the studs and tap the hole to be fully threaded. cut slot on end of stud. using screwdriver, tighten stud through clamp and into mounting nut. This will eliminate having to take tighten two lower nuts 12th turn at a time)screw and slot.

If you're doing damage and keep at it your only gonna do more.

Billy,your pump is Mercury and the parts are 100% different.
Yes not havin the coupler lined up right will give the same results.

 

[RRitt]

Re: Power Tilt/Trim question

Hey RRitt how about a pic of the( on 1988 remove the studs and tap the hole to be fully threaded. cut slot on end of stud. using screwdriver, tighten stud through clamp and into mounting nut. This will eliminate having to take tighten two lower nuts 12th turn at a time)screw and slot.

If you're doing damage and keep at it your only gonna do more.

Billy,your pump is Mercury and the parts are 100% different.
Yes not havin the coupler lined up right will give the same results.

I don't actually work on Force systems anymore ... just rebuild the valve bodies and sell a DIY kit for the cylinders. I'd probably quit the VB's if the chinese would offer a product that focused on quality rather than low price. Their 3w motor is decent enough and it can be sold for $75-$85. 3w has a common ground and an aluminum reservoir so it actually fights corrosion better than 2w (the motor frame has an electrical path through engine block to the sacrificial anode). If you use 4pin relays you can even use the 3w motor on a 2w boat. So there is no point working on trim motors. You can buy 2 chinese motors for less than the cost of one good prestolite repair and ... in the case of 3w motors ... the chinese product is good enough quality.

at any rate ...
the trim motor mounts to your transom clamp with three SS studs. If you extract these studs you see that the holes go all the way through the aluminum. In the factory, they were threaded from the outside and the threads stop after abt 1/4". If you use a tap then you can make all three holes fully threaded. If you use a dremel or something to cut a slot in the end of stud then you can turn it with a screwdriver. It is easier to thread the hole and use slotted studs than to fight a nut inside tight spaces. You save time in two ways ... you don't have to do a 12point turn on three nuts and you don't have the oil tubing fighting you against the studs (you can line up all the tubing with just one stud and do the other two later).

Didn't you have me rebuild a VB for you? Most of the shortcuts are described or hinted at in the instructions. Maybe I sent you an incomplete set? I could check to see what .pdfs I still have and send you. None of them have been fact checked in years. There may be some inaccuracies and errors but a good mechanic like you should get right by them.

 

[Justinde]

Re: Power Tilt/Trim question

Long and short of it, I'm going out the back tomorrow AM to remove the unit- I'll do it the slow way, as I don't mind doing 12 turn rotations- I am not confident to do the above- nor do I have a tap. I do have a vice and can complete the task as suggested......edit...... I just went up to the boat, if I take out the 4x bolts under the pump, and take the electric motor off, can I do it in situ? Do I need to remove the circlip to view the port, or is this visible from the underside???

 

[Justinde]

Re: Power Tilt/Trim question

Quick Question;-)

should there be a spacer on top of the electric motor inside the cover on top of the shaft?? Looks like I am missing one..... and I can't find a microfish or schematic of the electric motor internals, other than mentioning the bushes and springs.....??

 

[RRitt]

Re: Power Tilt/Trim question

Quick Question;-)

should there be a spacer on top of the electric motor inside the cover on top of the shaft?? Looks like I am missing one..... and I can't find a microfish or schematic of the electric motor internals, other than mentioning the bushes and springs.....??

assuming 1988 oem motor (plastic reservoir).

from top down:
plastic cap / brush card
end play shims (if any) on top of armature
no grease, the brass insert is self lubricating
armature into brushes
size 038 square cut oring
magnet frame dropped onto brush/armature assembly (wide space towards brushes)
size o38 square cut oring
reservoir assembly dropped onto motor frame and secured with a pair of through bolts.
through bolts should be sealed with bonded aluminum/nitrile sealing washers

before assembly:
looking down into reservoir is an oil seal pressed into top. If it has come loose, clean reservoir and gently press back into place using some oil-resistant locktite or adhesive. Inspect the sealing lip to make sure it is not crcked or damaged. There should be a small stainless steel spring pulling the lip against armature. the hole through reservoir should have a self lubricating brass bearing for the armature.

 

[Justinde]

Re: Power Tilt/Trim question

Thank you Rritt,

I don't have the end play shims- maybe I dropped them out?? Either way, can I replace them/it with a stainless steel ball bearing or similar? I had the motor pumping as stated above, then it would disengage, so the problem is the end shims not being there to 'hold' the pump in place, if that makes sense.

If you have any suggestions as to what I can use as a substitute, I will be back on the water once this is complete, and I don't want the trim unit to fail on the boat ramp or worse ...

 

[MickLovin]

Re: Power Tilt/Trim question

Just a question Justinde, have you looked at the parts picture on iboats regarding your model tilt trim, maybe you could determine from that if the shims are required, or you could stop being so tight and buy a new one (sorry Aussie humour)

 

[RRitt]

Re: Power Tilt/Trim question

Thank you Rritt,

I don't have the end play shims- maybe I dropped them out?? Either way, can I replace them/it with a stainless steel ball bearing or similar? I had the motor pumping as stated above, then it would disengage, so the problem is the end shims not being there to 'hold' the pump in place, if that makes sense.

If you have any suggestions as to what I can use as a substitute, I will be back on the water once this is complete, and I don't want the trim unit to fail on the boat ramp or worse ...

ball bearing won't work. You'll crack open the plastic top.
The actual low friction shims are almost impossible to get. I can't even remeber the name of plastic compound they are made from. They were expensive though. About $10 for a six pack.
SS washers won't work. They will rattle.
Fiberglass/resin washers work fine and withstand the heat but you have to be very careful
to get an exact diameter and a thin fit. McMaster Carr used to carry sme that were just perfect.
I think they were either 3/32 or 1/16th thick.

you have to turn motor upside down and measure the drop from face of reservoir to tip of armature. I don't remember the spec. Maybe is was 7/32min to 9/32max (??) IDK. The bottom line is that you want the tip of the armature to be 1/8th inch into the drive gear. You can figure it out with a caliper.

or ... you could just buy a chinese 3w motor for $75 and use four pin relays. That's what I would do. I'm lazy like that.

 

[Justinde]

Re: Power Tilt/Trim question

I could, but mine aint broke other than the shims.

I am going to go to the local Plastix Centre and ask then to make a shim for me based on my measurements.

You know that plastic '****' ( stuff) they use for cutting boards/berley boards or even bread boards??? That's the way I think I'll go, but I'll ask the shop for a high temperature resistant washer/shim for the application. . .


I can't thank you enough for your help, I was about to use suitably sized Stainless Steel Ball Bearings and would have failed.........