Author Topic: 1966 230SL Re-torque issue  (Read 158 times)

dnadanny1

  • Full Member
  • Junior Level
  • *
  • Hong Kong, North, Fanling, N.T.
  • Posts: 37
1966 230SL Re-torque issue
« on: February 15, 2020, 01:38:07 »
Hi All.

I have recently replaced my cylinder head and gasket. And, I heard that the cylinder bolts should be re-torque. However, I dont know how many miles should I drive before I re-torque my cylinder bolts.
Also, if I dont do the re-torque, what is the consequence that I should concern?

Any comment is appreciated.

Thanks,
Danny

Tyler S.

  • Full Member
  • Platinum
  • ******
  • USA, CA, Encinitas
  • Posts: 1526
Re: 1966 230SL Re-torque issue
« Reply #1 on: February 15, 2020, 02:48:11 »
The Retorque should be done within 500 miles. This is done because the torque value will change after a few heat/cool cycles. Failure to retorque the head bolts can result in a blown head gasket down the road. Be sure to retorque the head when the engine is hot. Then adjust the valves the next morning on a cold engine.
1968 (67) 250sl. 4 speed manual. DB180 Silver
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

ja17

  • Full Member
  • Platinum
  • ******
  • USA, OH, Blacklick
  • Posts: 6302
Re: 1966 230SL Re-torque issue
« Reply #2 on: February 15, 2020, 15:44:30 »
The head bolts on these cars are not "stretch type" so occasional re-torque will keep things to spec. Re-torque will also prevent head bolts from locking or rusting in place. Hopefully you oiled the bolt threads when you had the head off. Dry and oiled torque values will vary quite a bit. Lightly lubricating the threads will also prevent bolts from seizing. Be sure to release the radiator cap so there is no pressure in the cooling system before you begin. Loosen then re-torque each bolt one at a time in proper sequence. 
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

dnadanny1

  • Full Member
  • Junior Level
  • *
  • Hong Kong, North, Fanling, N.T.
  • Posts: 37
Re: 1966 230SL Re-torque issue
« Reply #3 on: February 16, 2020, 05:59:35 »
Thanks for input from both of you.

1) I have a tightening sequence graph provide by elring. Can I also follow the graph for re-torque?

2) When I re-torque, I should loose the bolt by how much? a turn? half a turn?

3) As I cant find graphite oil, I used ROCK PASSION's graphite grease lightly, e.g. between bolt and washer, thread of bolt. Is that ok?

Thanks again.,
Danny

Pawel66

  • Full Member
  • Platinum
  • ******
  • Poland, Mazowieckie, Konstancin-Jeziorna
  • Posts: 2191
Re: 1966 230SL Re-torque issue
« Reply #4 on: February 16, 2020, 08:53:48 »
You are a Full Member, please take a look here in our Technical Manual: https://www.sl113.org/wiki/Restricted/ValveAdjustmentTour#HeadBolt
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class