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280 DP-a steering pin protrusion measurement

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jrpowell3

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I have a 1986 VP DP-A I thought 290 but may be a 280. I need to know the measurement of how much the steering pin protrudes from the helmet. It started seizing up as it went back in but it seems bottomed when looking down the holes and trying to get a pick under the SS pin. It is about 1/4" out from the housing. Any one with similar drive that could send pic or take a measurement? Thanks, Richard
 
The pivot pin should be all the way down into the bearing carrier put a few drops of power steering fluid on the pin and alternately tighten the bolts and just pull it all the way down. It sounds like you may have it a little cocked in the housing the top of the bolts are close to flush on mine.
 
How about the SS steering pin itself? Does it lay flush? I thought mine was up a bit before I pulled everything apart and rebuilt everything. II will check tomorrow but I think the bolts do go all the way down. I forgot to clean overspray from the receiving hole and it either got cocked like you said or overspray made it too tight. I will pull and clean it up. I took it all the way down and repainted everything previous owner used copper bottom paint and no grounds.
 
If the two bolt holes line up you may be able to shimmy it in with a brass drift. You want at least five threads on the bolts before applying alot of torque or you risk stripping the threads in the double bearing carrier.
 
I smacked it with my brass hammer a couple of times when I re installed it. One screw lines up well and goes to the bottom the other one closest to the trans binds and doesn't quite go all the way down. I tried to post a pic but if fails each time. Maybe too large data? The cylinder sits up about 1/4" above the helmet and that's what really concerned me. Better to be safe than sorry just hate to use heat again on five coats of paint. I couldn't get a needle pick under the cylinder so I hoped it was bottomed out and I was ok. Thanks for your advice!
 
Finally got a photo to load IMG_4072 (2).jpg
 
Both bolts need to be flush. You cannot heat the pin you need to heat the bearing housing called the bearing box and not recommended you can damage the seal if it gets too hot. On my SP-MT basically the same gearbox the pivot pin is closer to flush with the helmet. They went from a single bolt to two bolts because of the stress and vibration I would confirm it is down tight and the bolts torqued to spec. You dont want it vibrating loose while under way.
 
Yes I heated the housing and iced the pin along with liberal PB Blaster to get it off the first time everything else I did correctly so now's not the time to cut corners. I'll measure everything with calipers so that I know it is seated. Thanks for your help!
 
jrpowell3 said:
I have a 1986 VP DP-A I thought 290 but may be a 280. I need to know the measurement of how much the steering pin protrudes from the helmet. It started seizing up as it went back in but it seems bottomed when looking down the holes and trying to get a pick under the SS pin. It is about 1/4" out from the housing. Any one with similar drive that could send pic or take a measurement? Thanks, Richard
Click to expand...

OK..... FYI:
As per your thread title ....... this is not a 280 DP-A drive. The 280 was never designated as an "A" model.
The 280 Duo Prop was introduced in 1983, and would have been equipped with the 280 style single helmet pin.
The helmet pin pictured is a double bolt pin.

What you have is a 290 DP-A noted by the transom shield, the suspension fork, the top cover, the double-bolt helmet pin and the 2 "bump-outs" on the bearing box/clamping collar!

NOTE: the two helmet pin bolts (3/8" NC socket head cap screws) must be of the correct length.
If too long, they will break through the A style aluminum bearing box/clamping collar, and will allow water to enter the universal drive shaft area! Use Caution here!!!!!!!!


If you have trouble removing the helmet pin, note the two small threaded holes @ 9:00 and @ 3:00 O'clock. These threaded holes are for "jack screws" . Clean the threads out, lubricate them, and install two long threaded grade #8 bolts and gently tighten each one equally.
The pin will be pushed outward.

Once out and with it still out......., install 1 cap screw into the female threads and gently tighten it.
Measure the length of the exposed cap screw shank area.
Compare this to the length of the helmet pin cap screw "bore" depth.
The exposed cap screw shank length should NOTexceed the pin bore depth!

If the shank length does exceed the bore depth, and if you were to use these cap screws, you will risk them bottoming out...... and worse yet, breaking the aluminum out into the universale drive shaft area!

Also note that the female threads are not aluminum....... these are thread inserts.
If you need to chase these threads, DO NOT use a thread cutting tap.
Instead, gently run a lubricated "roll tap" into them.
 

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