Transom/jackplate bolts?

[pyro]

What's the standard-issue recommendation for mounting bolts? Type/grade? Diameter/thread pitch? I will be replacing my L&S hydraulic with a Rapid Jack manual, so I will need some new bolts and nylock nuts to replace the studs in the old plate. Links are appreciated. Thanks in advance. :)

[1BadAction]

Cheapest way you're going to get the right **** is from Merc. 1/2" Fine thread SS bolts, washers, and bronze locknuts.

10-67755A22 BOLT KIT, Transom (2.50 Inch)


10-67755A26 BOLT KIT, Transom (3.50 Inch)


10-67755A13 BOLT KIT, Transom (4.50 Inch)


10-67755A14 BOLT KIT, Transom (5.50 Inch)


10-67755A15 BOLT KIT, Transom (6.50 Inch)


10-67755A17 BOLT KIT, Transom (7.50 Inch)


10-67755A18 BOLT KIT, Transom (8.00 Inches)

I believe the kits are all in quantities of 4. 4 bolts, wide washers, narrow washers, and nuts. The washers themselves are also thicker than normal hardware.

[panther150]

If you do not use brass nuts , make sure you put some lube on the stainless nuts, nyloks, as it will gaul without it. I use a White thread sealer with PTFE, works great.

Steve

[capteliminator]

1badaction nailed it, use the merc stuff. Heavy duty hardware along with brass nuts.

[powerabout]

those nuts are not brass, they are bronze, or they should be, brass is crap

[tlwjkw]

a "touch" of anti-seize on stainless bolts ALWAYS works out in tha long run......

[Dave Strong]

a "touch" of anti-seize on stainless bolts ALWAYS works out in tha long run......

:iagree: And NO air tools. ;)

Dave :)

[Ted Stryker]

All good info, proving advice.. I use 1/2"x20 stainless with stainless nyloks but I use anti-seize.. I put the nut in the inside of the transom in case I need to ever re-torque, I won't lose my water tight seal long as I keep the bolt from turning.. I have used grade8 fasteners but I sure wouldn't recommend it in salt..
And don't over torque, use big thick washers

[Slimm]

I bought all new stainless steel bolts, nuts and washers when I re-powered my boat. I then learned that stainless steel hardware was grade 5, shortly before bolting everything up I saw a couple videos of engines coming loose from the transom due to broken bolts or nuts coming loose. I chose to buy everything in grade 8 since I am not in saltwater and used anti-seize liberally when bolting everything up and again whenever I changed jackplates or added wedges etc.. I am sure some folks do theirs differently but after seeing those engines flopping around the boats with props spinning, I knew real quick I didn't want that thing in the boat with me.

Slimm

[powerabout]

I thought those OMC V8 bolts are equivalent to grade 8 steel?

[Euroski]

From memory it's 60ft/lbs torque

[vnemous]

No anti size in salt water JMO

[Dave Strong]

From memory it's 60ft/lbs torque

30 lb/ft.

Dave

[pyro]

Awesome. I will see what lengths I need, and order the Mercury kit.

Currently, there are NOT any washers on the motor side at all, just nylock nuts.

[powerabout]

I wonder if 400 verado uses the same bolts?

[JPEROG]

Stainless will stretch and the plate will loosen over time if you run hard. I have learned first hand and had to drill and sleeve the elongated holes in my transom on my 28 skater. Grade 8, backing plates inside and out so you don't crush the transom glass and you are done. Watch the videos of offshore outboards and you can see that they want off the back of that boat when things get rough.

Joe

[patchesII]

I use grade 8 hardware

[Ziemer]

McMaster Carr has about anything you can imagine when it comes to fasteners. Plus, most of it is in stock and ships same day.

[FUJIMO]

No anti size in salt water JMO
...Agreed. I have used and recommended Tef-Gel, ever since they came out with it, back in the 90's. www.TefGel.com

[powerabout]

I use tef gel when I am on the dark side ( race yachts) to prevent corrosion when putting fasteners into Carbon
Carbon will eat through a stainless bolt while you look at it if you add a little salt water

[Revolution141]

I run hard offshore. Was bending and breaking stainless 1/2" bolts all the time (and smashing jack plates). Ended up making my own static setback and drilled everything on the transom side 3/4" and used s/s hardware. On the engine side I double bolted top and singled the bottom but used 15mm s/s bolts (the merc holes are spot on 15mm). Holes in plate had to be perfectly aligned for the 15mm bolts but never had any issues with the washers mushrooming again.
3/4" was a little over kill, if I did it again I'd just go 5/8".
its hard to over size the holes on a lot of pre made jack plates.

[pyro]

Does anyone know off-hand how thick the factory transom is on my Vegas XT? I want to do this jackplate swap all at once, but I don't know which length of bolts I will need. I have 1/4" aluminum backing plates and thin stainless washers on both pairs of mounting bolts for the inside. The jackplate metal is around 3/8" thick.

Any suggestions? Thanks.

[FUJIMO]

Does anyone know off-hand how thick the factory transom is on my Vegas XT? I want to do this jackplate swap all at once, but I don't know which length of bolts I will need. I have 1/4" aluminum backing plates and thin stainless washers on both pairs of mounting bolts for the inside. The jackplate metal is around 3/8" thick.

Any suggestions? Thanks.
Push a bolt through an existing transom hole, mark the other end of it with masking tape or a majic marker, pull the bolt back out and measure the thickness of your transom.

[derpid]

I just mounted my 225 rude and I used gr 8 fine thread bolts on the transom and set back spacers. check into manufacturers specs for bolt torque, for my engine it was 60ft lbs.