Locknuts

[spbutler]

I installed new Bobs 10 inch setback
jackplate last year.
I checked jackplate bolts to transom a couple weeks ago and got about a quarter turn on all 4.
Used boat for a long weekend.
Checked bolts again today and got a good half turn.
I didn't use a torque wrench either time.
I'm thinking maybe I over torqued the lock nuts.
I did use marine anti seize on installation.

I think I should replace the locknuts and use the torque wrench and was wondering if that is enough or can I use loctite with locknuts?



ARP high strength bolts and nuts is what I used.

Bobs jackplate bolts come with lock washers and locknuts.
I emailed them about their bolt kit and they state the lockwashers go on the bolt head side.

Thanks for any better suggestions.

[NICE PAIR]

I installed new Bobs 10 inch setback
jackplate last year.
I checked jackplate bolts to transom a couple weeks ago and got about a quarter turn on all 4.
Used boat for a long weekend.
Checked bolts again today and got a good half turn.
I didn't use a torque wrench either time.
I'm thinking maybe I over torqued the lock nuts.
I did use marine anti seize on installation.

I think I should replace the locknuts and use the torque wrench and was wondering if that is enough or can I use loctite with locknuts?



ARP high strength bolts and nuts is what I used.

Bobs jackplate bolts come with lock washers and locknuts.
I emailed them about their bolt kit and they state the lockwashers go on the bolt head side.

Thanks for any better suggestions.

How large are the back up washers on the inside of transom? If just 1/2" washers, I'd suggest aluminum plates 3"x3" (can be larger, one plate per two bolts)

Does the transom show collapsing or being crushed inside or outside?

How old is the boat?

Does the transom seem solid?

[spbutler]

Transom is solid, I repaired it a few years ago and theres an aluminum backing plate in the splash well and 4 x 6 inch inside the bilge area.
I'm going to check with my torq wrench and see if I can tell how tight but I would say about as tight as I do lug nuts.
I was reading 90 ft lbs is suggested

[NICE PAIR]

Transom is solid, I repaired it a few years ago and theres an aluminum backing plate in the splash well and 4 x 6 inch inside the bilge area.
I'm going to check with my torq wrench and see if I can tell how tight but I would say about as tight as I do lug nuts.
I was reading 90 ft lbs is suggested

Sounds as though you've done a good job. you have extended the leverage arm, so some compression change would be expected. I have rebuilt a few transoms and experienced the changes that you are talking about. I don't think I've ever torqued the transom bolts but I do inspect them regularly, looking for loose, compressed, sliding or movement marks.

one more question - fine thread or coarse thread?

[spbutler]

Coarse, after further thought, I'm thinking I may have just used 2 wrenches last time and I used a 1/2" ratchet yesterday.
I marked bolts and will check after this weekend.
Thanks, sorry about any confusion.
I just realized this now.
I ordered new arp nuts anyway and will replace if they move al

[LakeFever]

Common. When the fasteners set on the aluminum and washers in a stack like this they tend to settle in a little and seems like they came loose but its the settling in. On my new build I had to tweak them tighter twice. I check after every time out I am fastidious in checking all fasteners on my stuff. After the first couple times they have been tight no issues now. Although 90 lbs' seems extremely high for jack to transom? 30 lbs' is more like it. You dont want to crack your glass. If your tightening and you hear cracking noises? You got troubles that may cause loosening bolts among other things

[spbutler]

I think I just got more torq this time.
I'll check and if they don't move after this weekend I'll repkace nuts after the season thanks.
Transom has 3/16 aluminum plate and transom was saturated with epoxy resin and cabisol.
It's like a brick wall now.
Also added several layers of 1708 and epoxy on the inside of transom.