300 tdi conrod bolts

ibest · 6th August 2007, 07:18 PM

I am in the process of an in chassis ring and big end rebuild of my 300 tdi and the Haynes maual tells me to replace the big end bolts and nuts. Alto Spares have never sold a set and would have to source from U.K. Does this mean it is not necessary and they are generally not replaced or that they are always sourced elsewhere due to price or for some other reason.If sourced elsewhere,from whom?

**rangieman** · 6th August 2007, 07:24 PM

Do alto spares do repairs if they do ask them if they replace the bolts when doing the bearings
Ive never replaced conrod bolts in the past

**Blknight.aus** · 6th August 2007, 07:30 PM

I replace all the bolts in the bottom end of the engine and the head bolts as well when Im doing a rebuild as its cheap insurance.

If its not a manufacturers requirement and Im doing it for some one else I tell them that if they dont want to do it then they can save maybe a hundred bucks on the rebuild but run the risk of the bolts letting go at a later (or sooner) point.

I have snapped a big end bolt on a rebuild (didnt that cause some merry hell to get out) and i suspect that it had been overtightened before I took it out, close inspection of all the bolts showed signs of stress on the threads nearest the head.

I havent had one snap or loosen on me after a rebuild yet and I dont want to find out the end result of it happening so i replace the bolts.

**Bigbjorn** · 6th August 2007, 08:57 PM

First question. Is it a special bolt? That is, does it have a non standard head? If so you may probably have to pay up and shut up if it is an OEM exclusive bolt. Next question, if a special head shape, can you fettle a standard hex or socket head bolt to fit? Next question. Is the recommended torquing procedure one of tightening to a specified level of tension, or one of tightening to a measured dimension of stretch?

Ee bah goom , mooch prefer stoods and noots to bolts meeself, Gaffer. Noo gannin doon t' poob to hear pithead braas bund. Ooh, Ey.

**roverrescue** · 6th August 2007, 09:44 PM

My first 300tdi "bad experience" was when no.1 big end bolt sheared its head (whilst driving), allowing the bearing to spin, blocking an oil passage... leading to just a shade of damage. Donk had 225k or so. If I was in there Id be a replacing them, maybe call a place that rebuilds the tdi's regularly and see what they say?

regards
Steve

ibest · 7th August 2007, 04:01 PM

Originally Posted by Brian Hjelm

First question. Is it a special bolt? That is, does it have a non standard head? If so you may probably have to pay up and shut up if it is an OEM exclusive bolt. Next question, if a special head shape, can you fettle a standard hex or socket head bolt to fit? Next question. Is the recommended torquing procedure one of tightening to a specified level of tension, or one of tightening to a measured dimension of stretch?

Ee bah goom , mooch prefer stoods and noots to bolts meeself, Gaffer. Noo gannin doon t' poob to hear pithead braas bund. Ooh, Ey.

Thanks Brian, To answer your questions the bolts are specific and therefore probably only OEM available and they have a torque spec of 59 nm.
Cheers Ian

ibest · 7th August 2007, 04:08 PM

Originally Posted by roverrescue

My first 300tdi "bad experience" was when no.1 big end bolt sheared its head (whilst driving), allowing the bearing to spin, blocking an oil passage... leading to just a shade of damage. Donk had 225k or so. If I was in there Id be a replacing them, maybe call a place that rebuilds the tdi's regularly and see what they say?

regards
Steve

Just one story of that sort of failure is enough to convince me to replace them ! I don't know the cost yet but I will pay it for peace of mind. It just seemed odd that a major L.R. parts supplier had never sold any.

**stuart** · 7th August 2007, 05:00 PM

Hey,

ETC7357 Bolt-conrod you need 8 only have 5 sold a few over the years
ETC8191 Nut-conrod plenty of stock sell a few
ERR2418 Conrod have stock and sold a few over the years...

stuart@rovacraft.com.au

Originally Posted by ibest

I am in the process of an in chassis ring and big end rebuild of my 300 tdi and the Haynes maual tells me to replace the big end bolts and nuts. Alto Spares have never sold a set and would have to source from U.K. Does this mean it is not necessary and they are generally not replaced or that they are always sourced elsewhere due to price or for some other reason.If sourced elsewhere,from whom?

ibest · 7th August 2007, 06:01 PM

Originally Posted by stuart

Hey,

ETC7357 Bolt-conrod you need 8 only have 5 sold a few over the years
ETC8191 Nut-conrod plenty of stock sell a few
ERR2418 Conrod have stock and sold a few over the years...

stuart@rovacraft.com.au

Thanks for the feedback chaps, I will go new and sleep easier. Pity Perth is so far from Sydney Stuart,but thanks for the info.
Regards. Ian

**Blknight.aus** · 7th August 2007, 06:06 PM

yes they are a specific bolt but there are places that sell appropriate substitutes (bolt master in townsville for one) and these guys know their bolts so if you take in one and say i want a replacement for one of these, It does this, in that bit there and gets tensioned to thus and so NM they should be able to help you out or say "no mate Goe OEM we dont stock said beasty.

normally they are tightened to HFTT(holy @#$k Thats Tight) using the Torque angle method or a BA torque wrench.

to do this simply tighten (in the correct sequence and stages (read the tools thread i started a while back)) with a torque wrench to a set torque then, again in the correct sequence and stages, tighten the bolts up a set number of degrees.

for 30 degrees or less its one stage, between 30 and 60 its two stages and from 90 to 180 degrees it should be done in three stages. I have never come across bolts that go more than 180 deg past the preset torque but if it did happen Id probabley make 4 passes.

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