12ht big end bearing numbers

[pistonslaps]

Toyota 12ht engine ..can anyone tell me what the numbers mean ?

 

[roma042987]

Appears to be 1mm oversize

 

[OGBeno]

D8L D + manufacturing date and plate code. I assume this is from an engine manufactured in 1988?

1 = bearing size, AKA: MARK 1

For the BEB's on a 12H-T, you only have two possible bearing size options: Mark 1 or Mark 2. The bearings will indicate what size replacement as long as you are not machining the crank, then you would go with a bearing sized kit (.25/.50/.75/1.0mm under). At least from Toyota.

 

[pistonslaps]

D8L D + manufacturing date and plate code. I assume this is from an engine manufactured in 1988?

1 = bearing size, AKA: MARK 1

For the BEB's on a 12H-T, you only have two possible bearing size options: Mark 1 or Mark 2. The bearings will indicate what size replacement as long as you are not machining the crank, then you would go with a bearing sized kit (.25/.50/.75/1.0mm under). At least from Toyota.

hey thanxs for that info ...i googled the numbers ..and coudnt find ...so it looks like there rigidij originals ...i can see crosshatch in the bores ..so i mite get a few more cliks out of her ..i am pretty excited about a 30 year old engine lol

 

[HueyDriver]

D8L D + manufacturing date and plate code. I assume this is from an engine manufactured in 1988?

1 = bearing size, AKA: MARK 1

For the BEB's on a 12H-T, you only have two possible bearing size options: Mark 1 or Mark 2. The bearings will indicate what size replacement as long as you are not machining the crank, then you would go with a bearing sized kit (.25/.50/.75/1.0mm under). At least from Toyota.

Reviving an old thread here because I am curious.

Lets say you have a MARK 1 bearing and you have your crank turned/machined. Do you need to buy a specific MARK 1 bearing sized kit that is .25 (or .50, or whatever you need) sized under? Or is there a generic bearing sized kit that is able to be replaced with MARK 1 or MARK 2?

For example (on a 12HT), I see 4 part numbers which seem to be:

11704-68021 (U/S 0.25)
11705-68021 (U/S 0.50)
11706-68021 (U/S 0.75)
11707-68021 (U/S 1.00)

Are these MARK 1 or MARK 2?

Broken down even further (from partsouq) I see the "MARK" listed:

11071-68020-01	12HT,2H..HJ6# NO.2,MARK 1
11071-68020-02	12HT,2H..HJ6# NO.2,MARK 2,MARK 2
11071-68020-03	12HT,2H..HJ6# NO.2,MARK 3,MARK 3
11701-68020-01	12HT,2H..HJ6# NO.1,MARK 1,MARK 1
11701-68020-02	12HT,2H..HJ6# NO.1,MARK 2,MARK 2
11701-68020-03	12HT,2H..HJ6# NO.1,MARK 3,MARK 3

Now I see these are listed as MARK 1/2 or 3, but which of these above is undersized and to what size?

Thanks.