33GTST rebuild

[Joeydw]

Hey guys,

Looking at doing a rebuild of my RB25DET because I recently found out that i've got some pretty excessive crankshaft end float (1mm). Just wanted some guidance/tips before I start pulling stuff apart.

Just a little bit about the car:

- was apparently rebuilt by previous owner about 15,000km ago. There's 200,000km on the chassis.

- HKS 3071 turbo. Running 14psi

- Stainless FMIC

- Tomei Poncams

1. What could've caused the end float? Was it from the rebuild not being done right?

2. What other maintenace items should I check off while I've got the engine pulled apart?

 

THANKS!

[Rusty Nuts]

1 hour ago, Joeydw said:

. What could've caused the end float? Was it from the rebuild not being done right?

Number 4 main bearing (centre bearing) controls end float, the maximum float is 0.3mm. During a rebuild the end float is measured with a dial gauge using a new bearing in place, if the float exceeds the maximum the crank should be replaced. Standard float is usually 0.05 to 0.18mm. So would suggest the rebuild was not done right or the crank needs replacing.

[Joeydw]

 

12 hours ago, Rusty Nuts said:

Number 4 main bearing (centre bearing) controls end float, the maximum float is 0.3mm. During a rebuild the end float is measured with a dial gauge using a new bearing in place, if the float exceeds the maximum the crank should be replaced. Standard float is usually 0.05 to 0.18mm. So would suggest the rebuild was not done right or the crank needs replacing.

Thank you Rusty,

I've also read it may have to do with starting the car with the clutch pressed ?(rookie mistake). In my defence, the car did have an exedy triple plate in there with ridiculous clamp so a lot of the time, i'd be just restarting it without much thought into where my left foot was.

On the flip side, I've only owned it for just over a month and in that time, i've only taken it for about 3-4 short drives around my local streets soo...

Could the end float be caused by that or more likely the rebuild was not done right in the first place?

[GTSBoy]

You're not going to wear out the thrust in that time with that usage. It was probably put back together without even checking it.

[Rusty Nuts]

The centre bearing thrust face is not pressure fed with oil, the sides of the bearing rely on dripping oil for lubrication, extended clutch riding can have an effect on end float ,the crank thrust bearings can withstand a shedload of force but they can't do  it for long periods.So while they can handle the heavy but intermittent loads produced by a super heavy duty pressure plate without problems a continuous load can wipe them out. As GTSBoy said its doubtful you have caused this, But more likely a previous owner with poor driving skills over an extended period.