Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

New vs old tensioners

 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech.
View previous topic :: View next topic  
Author Message
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Tue Jan 09, 2018 5:41 am    Post subject: New vs old tensioners Reply with quote

So I've seen posts where people are replacing their timing belt tensioner and mention the new vs the old one, needing a different bolt, etc. Can someone tell me what the difference is between them, if there are different ones between turbo and NA, etc? I have a new tensioner, it looks identical to the old one, but the old bolt won't go through the hole, whereas it fits easily into the hole in the older one. I can't imagine this is the difference though...that bolt still needs to thread into the block.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Zuffen  



Joined: 31 Jul 2001
Posts: 1421
Location: Owasso, Oklahoma 74055

PostPosted: Fri Jan 12, 2018 3:07 pm    Post subject: Reply with quote

Do you have a pic of the old and the new? The original is the hex head off set, and the new is still offset but with two holes for a spanner wrench. This is common audi part and i think the revision requires a stud with a nut vs the original bolt.
_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951
Back to top
View user's profile Send private message Send e-mail
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Sat Jan 13, 2018 1:42 am    Post subject: Reply with quote

I don't have a picture, but they look identical. Both have the two holes for the special tool (which I found for like $ and neither have the offset hex head. Just looking at the holes, they don't look so different, but they are measurably different...the new one is maybe 0.5mm smaller.

I'm guessing I need a stud with this...someone pointed out that Advanced Auto Parts actually carries the stud, so I ordered it. I assume I can just get a nut and washer that fits from the hardware store...part numbers were specified on the site but they didn't seem to carry them.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Carrera RSR  



Joined: 08 Jan 2010
Posts: 1598
Location: Somerset, UK

PostPosted: Sat Jan 13, 2018 2:25 am    Post subject: Reply with quote

Tensioner quality/tolerance issue? Does not matter whether you use a stud or bolt, they will both need the same size hole in the tensioner to successfully mount it.
_________________
1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Sat Jan 13, 2018 3:07 am    Post subject: Reply with quote

Well, that's true if both sides of the stud are the same. It is conceivable that they are not, I suppose. If not, then there's no way this tensioner could ever work as the threaded hole is this size. Someone suggested I check for a helicoil in case someone previously stripped it out. I suppose they could have enlarged the hole in the tensioner at that point, but I see no evidence of that. Probably more likely that it's a tolerance issue as you say, or a slightly different part mistakenly made it out of the warehouse.

Carrera RSR wrote:
Tensioner quality/tolerance issue? Does not matter whether you use a stud or bolt, they will both need the same size hole in the tensioner to successfully mount it.

_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
jazz guy  



Joined: 26 Nov 2002
Posts: 384
Location: Colorado

PostPosted: Sat Jan 13, 2018 8:01 am    Post subject: Reply with quote

Zuffen wrote:
Do you have a pic of the old and the new? The original is the hex head off set, and the new is still offset but with two holes for a spanner wrench.

Hi Bob, it's good to see you on the board. As Bob said the early style tensioner had a hex protrusion to use a wrench to tension it. The late style has the two holes for the tensioning tool. I think all tensioners have superceded to the "late" style.

bureau13 wrote:
I'm guessing I need a stud with this...

I usually buy a kit with the tensioner, stud, washer & nut. "Here" are some examples with pics to click on (not an endorsement). I believe the studs are threaded the same on both ends, but I guess I'm not quite clear on your issue. Are you saying the hole into the head is too large and your stud won't thread in? Or, is the hole through the new tensioner itself is not right?
_________________
'81 931
'82 931
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Sat Jan 13, 2018 12:43 pm    Post subject: Reply with quote

Well the stud just arrived today. It is visibly smaller than the bolt that was in there before. The stud goes through the new tensioner just fine, and I can thread it into the thermostat housing, or wherever it's supposed to go...which surprised me. It's smaller but still threading in...but it's not really tight in there. Someone suggested maybe it was previously stripped and there's a helicoil, but I don't see one. Honestly, I'm at a bit of a loss. Tempted to just put the old tensioner back on with the old bolt.
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Tue Jan 16, 2018 1:19 am    Post subject: Reply with quote

OK, here's my cunning plan. I'm re-using the old tensioner and bolt, since it seems fine, and THEORETICALLY, since this is supposed to be an easy job (ಠ_ಠ) if/when it starts making noise, or the water pump I'm also not yet replacing starts leaking or otherwise failing, I can deal with it then. But, HOW do I deal with it then? Well, I was wrong earlier when I said it was screwed into the block, as I'm sure you all know. It's the thermostat housing, I think. So, the plan would be at that time to replace the whole housing. Is that a terrible job? It doesn't SEEM like it would be that bad...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Paul  



Joined: 02 Nov 2002
Posts: 9348
Location: Southeast Wisconsin

PostPosted: Tue Jan 16, 2018 3:33 am    Post subject: Reply with quote

Easy to do, the hardest part is cleaning the gasket surfaces.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Back to top
View user's profile Send private message Send e-mail
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Tue Jan 16, 2018 7:20 am    Post subject: Reply with quote

A bigger worry might be how hard it is to find the part. Apparently it's NLA from Porsche (or VW/Audi). I see one on Ebay for $124 but I have no idea if that's a good price. It's more than I really want to pay for something I don't need right this minute, but I'd hate to need one and be unable to find it...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Stunter  



Joined: 09 Jan 2018
Posts: 7
Location: Hot Springs, AR

PostPosted: Tue Jan 16, 2018 7:52 am    Post subject: Reply with quote

Hey Bureau, I'm the one who posted about the possible stud issue on rennlist. I would take the bolt down to the local hardware store and size it. It should be an M10 which is also the same size the stud is supposed to be. Maybe the previous owner just drilled the hole out and retapped the next size up. If it is incorrect, you could always helicoil it back to the stock size of M10 or weld it full and re-drill and tap. Lot of work, but it is options.

I finally got my car home, and have ordered all the parts. I will let you know what I find when I tackle the timing belt in the next week or so.
_________________
'81 931
Back to top
View user's profile Send private message
bureau13  



Joined: 07 Sep 2017
Posts: 81
Location: South Florida

PostPosted: Tue Jan 16, 2018 9:51 am    Post subject: Reply with quote

That's a good idea...hadn't thought about the option of inserting a helicoil or similar in that hole, so the stud will fit. Definitely an option at some point.

When you do the timing belt, I'll be interested to see if you have any issues getting the belt to wrap around the crank gear properly. No one has seemed to have problems with this but me...
_________________
-----------------------------------------
1982 931
1986.5 Silver 928S
2007 Hummer H3 (Daily Driver)

Past lives (I miss them all):
2004 RX-8 (Wrecked)
1993 RX-7 (Sold)
1987 RX-7 Turbo II (Sold)
1985 RX-7 GSL (Stolen)
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech. All times are GMT + 11 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group