Installing Gudgeons

Post by **Spud76** » Fri Jul 21, 2006 1:23 pm

Hi I am about to start puttin my 3l toyota engine back together and the gudgeons are really hard to get into the new little end bushes.

was gunna through the gudgeons in the freezer and put the conrods in the oven for a while but thought i would just ask in case their is a dead easy way to get em in i don't know about.

Post by **"CANADA"** » Fri Jul 21, 2006 1:25 pm

Are they the correct pins?

Define "End bush's"

Post by **Spud76** » Fri Jul 21, 2006 1:30 pm

yeah there the right pins the came with the new pistons and the replacement little end bushes
The little end bushes are the bushes that press into the little end of the conrods. I think they are brass lined jobbies they seem a little rough to me but the bloke who pressed em in for me at the engine rebuilders said thats how they come and the are softer than the gudgeons and will settle in. I think thats why the are hard to get in but.

Post by **"CANADA"** » Fri Jul 21, 2006 1:34 pm

Bit of oil...How hard are they to get it..or are they physicly bigger and wont go?

Post by **Spud76** » Fri Jul 21, 2006 1:40 pm

They seem to be the exact size with zero tolerance and i don't want to score the bushes by forcing them. tryed oilin em still don't slide in.

Post by **GutSquisher Media** » Fri Jul 21, 2006 1:47 pm

They are ment to be a snug fit but not tight. If you pressed in new bushes on the rod ends you will need to hone them down to spec.

Post by **Spud76** » Fri Jul 21, 2006 1:50 pm

no worries thanks for that gutsquisher

Post by **-Scott-** » Fri Jul 21, 2006 1:55 pm

Gudgeons need to be an interference fit somewhere, or they'll move sideways and drag on the bore. Generally they're pressed to the conrod, so the sliding joint has a larger bearing surface.

Find a spec for honing, don't try for a fit which can be hand assembled. I would expect the fit to be different for brass bush instead of direct to steel conrod - make sure you get the right figure.

Cheers,

Scott

Post by **Patchy** » Fri Jul 21, 2006 1:58 pm

if you have some rough edges that you suspect is stoping the pins from going in try some fine wet and dry and take them off, if there brass shouldnt take much at all. just dont go over board.

just coz something come in a kit doesnt mean squat, i would still be checking everything: ring clearances, bearing gaps everything. And every time you put a piston into the engine turn it over, the last thing you want to do is get to the end and have and engine that wont turn over.

if your still unsure as to the the gudgeons take it to the engine rebuilder. if you put it together and there turns out to be a problem with it, he will put it down to incorect assembly and it will be up to you to sort it out. better to be safe than sorry.

Post by **Spud76** » Fri Jul 21, 2006 1:59 pm

the ones i pulled out where not pressed in the where free to slide and are held in position with circlips so they don't pertrude pastthe side oof the piston.
once i removed the circlips the old ones simply pushed out of the piston and conrod with your finger.

Post by **-Scott-** » Fri Jul 21, 2006 2:01 pm

Spud76 wrote:the ones i pulled out where not pressed in the where free to slide and are held in position with circlips so they don't pertrude pastthe side oof the piston.
once i removed the circlips the old ones simply pushed out of the piston and conrod with your finger.

Interesting - I've not seen that - but I haven't seen that many either, so it's not really surprising.

Cheers,

Scott

Post by **Spud76** » Fri Jul 21, 2006 2:05 pm

Thanks patchy will check it carefully have the engine spec sheet there.

Post by **"CANADA"** » Fri Jul 21, 2006 2:11 pm

So your new pistons have no circlip

Post by **Spud76** » Fri Jul 21, 2006 2:19 pm

yeah they do they are just tight

Post by **Ruffy** » Fri Jul 21, 2006 3:29 pm

I'd suggest taking your pistons, gudgeons and rods to a machine shop and ask them to fir them. Shouldn't cost too much at all.
If you hone them and get a little to excited they'll be noisey and wear prematurely. If they have circlips they should be a zero tolerance fit or slight interference (requiring gentle tap).

If you're not 100% sure get some one who knows to do it or you may regret it.
Cheers

Post by **360 scout** » Fri Jul 21, 2006 7:02 pm

STOP

Floating gudgeon pins:
do not attempt to fit the pins buy honing the bushes your self , gudgeon bushes are supplied semi finished to allow for the tolerence on the bore in the conrod , they must be honed or preferably bored in a machine as there are alignment issues to deal with,if the pin is slightly cocked to one side the piston will not sit straight in the bore the pin willalso thrust against one circlip & can actually hammer out the circlip groove, & the circlip will fall out not pretty

.
correct fit is about .0005' from memory the pin should slide through slowly under it's own weight when held on the side , also check the bush is parralel
after its bored push pin half way through & see if theres any movement.
Cheers Andrew

Post by **Ruffy** » Fri Jul 21, 2006 7:37 pm

360 scout wrote:STOP Floating gudgeon pins:
do not attempt to fit the pins buy honing the bushes your self , gudgeon bushes are supplied semi finished to allow for the tolerence on the bore in the conrod , they must be honed or preferably bored in a machine as there are alignment issues to deal with,if the pin is slightly cocked to one side the piston will not sit straight in the bore the pin willalso thrust against one circlip & can actually hammer out the circlip groove, & the circlip will fall out not pretty .
correct fit is about .0005' from memory the pin should slide through slowly under it's own weight when held on the side , also check the bush is parralel
after its bored push pin half way through & see if theres any movement.
Cheers Andrew

What he said!..

Post by **plowy** » Fri Jul 21, 2006 7:53 pm

Post by **460cixy** » Fri Jul 21, 2006 9:38 pm

yup there gotta be reemed to size

Post by **V8Patrol** » Fri Jul 21, 2006 10:36 pm

Take it to an engine specialist .......

Do NOT attempt this at home ........

Its money well spent !

the cost could well be ya motor either being a "new motor " or a boat anchor.

READ THIS AGAIN .......

360 scout wrote:
STOP Floating gudgeon pins:
do not attempt to fit the pins buy honing the bushes your self , gudgeon bushes are supplied semi finished to allow for the tolerence on the bore in the conrod , they must be honed or preferably bored in a machine as there are alignment issues to deal with,if the pin is slightly cocked to one side the piston will not sit straight in the bore the pin willalso thrust against one circlip & can actually hammer out the circlip groove, & the circlip will fall out not pretty .
correct fit is about .0005' from memory the pin should slide through slowly under it's own weight when held on the side , also check the bush is parralel
after its bored push pin half way through & see if theres any movement.
Cheers Andrew

You NEED specialist gear and the KNOWHOW to use it correctly

Kingy

Post by **Spud76** » Mon Jul 24, 2006 9:27 am

Cheers for the advise guys took them back to the rebuilders and he honed them down for me on the weekend engine is back in one piece now ready to drop back into the wagon.
Pete

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Installing Gudgeons

Installing Gudgeons

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