Life Of A Cam And Crank Seal?

[dchan865]

Hey folks,

I've been doing my timing belt homework so I know opinion varies regarding what should be replaced when doing the timing belt replacement.

Until now I've never hear the need to replace the cam and crank seal(one service guy recommendeded it but I am not sure if he is trying to sell me some BS). I do understand that it will eventually break down over time/mileage. As a matter of fact, I never hear of anyone reporting having problem that resulted in a bad seal.

Does anyone know or have an opinion/experience on how long this part usually last? What are the chances that it will last 200K miles(hopefully on a 2nd timing belt replacement) in normal driving(80% freeway and no towing) condition? I know its not easy getting an objective answer.

thanks any feedback!

[mann777]

Hey folks,

I've been doing my timing belt homework so I know opinion varies regarding what should be replaced when doing the timing belt replacement.

Until now I've never hear the need to replace the cam and crank seal(one service guy recommendeded it but I am not sure if he is trying to sell me some BS). I do understand that it will eventually break down over time/mileage. As a matter of fact, I never hear of anyone reporting having problem that resulted in a bad seal.

Does anyone know or have an opinion/experience on how long this part usually last? What are the chances that it will last 200K miles(hopefully on a 2nd timing belt replacement) in normal driving(80% freeway and no towing) condition? I know its not easy getting an objective answer.

thanks any feedback!

Since you have already covered on the Timing belt, I would not go into the detail. Now coming to the replacement of Crank Seal, the replacement is only done when there is a oil leak. The seepage starts around the main pulley towards the bottom of the engine. To replace it is not rocket science, Yes there are few obtacles that needs to be removed in order to have a decent space for the removal of the main pulley, All you need is a crankshaft pulleypuller. Now one thing is quite important to note while using this tool, the seal is rite behind the pulley once removed, so this has to be done quite slowly, by giving a few taps( wood mallet or fibre) around quite mild, so that you dont damage the surface and and then you slide the new one in and tap it evenly into place. The Cams replacement I have not heard of replacement even on high mileage, unless you have a total dead compression, My LS400 has reached 323000 miles and to date I have not done anything to it, and rest replacement as per the books have stuck to it, and still runs like a top.

[dchan865]

Mann777, nice to know your LS400 has gotten that far, simply amazing how well the Toyota engines can last.

I hope mine can last this long. One Lexus dealer try to sell me timing belt package deal($1900) which consist of Tbelt, WP, drive belt, cam and crank seals, tensioner and other idler parts. I've decided against it and left out the Cam and Crank seals(all appeared good during inspection). And I ended up taking it to a Toyota dealer for a resonable price.

Now speaking of the T-belt. That belt still look good after 106K miles, the teeth were intact,no cracks or belt fiber coming apart which I was surprise how robust it is. My guess is I can probably go further without the Tbelt replacement but this is something I didn't want to gamble on.

[mann777]

if you want to take the gamble then you should focus more on the T/Belt Tensioner Assy and the Chain tensioner ( regular visual inspection once after it crosses 100k) as that is the root cause for having the T,belt life depletion, As the spring tensile within becomes weak, it has a direct impact on the T/Belt life expectancy. The belt wear & tear is faster, that is why the whole lot set is asked to replace along with the T/Belt.

[NNaidu]

Hi,

Do you have a procedure to replace the timing belt (with pictures or lexus manual) on a 2004 GX-470, mine is just about 108k miles and it is time for the replacement. The dealer wants 550dollars + parts.

I think I can do it my self with correct procedure.

[lenore]

As for the crank seal it can wear a groove in the surface of the crankshaft. However there is a stainless sleeve which can be put over the crankshaft end to eliminate the worn spot...personally if the groove is not bad, i would use 800 grit wet paper and smooth the imperfection out and try a new seal...

[dchan865]

Just a quick comment about the Crank and Cam seals. On my 2nd round of timing belt replacement, I wanted dealer to replaced both. However, only the crank seal was replaced. According to dealer, it would be very time consuming to tear down additional parts to replace  the Cam seals b/c more parts have to be taken out, so obviously that'd drive up the cost.  Watching a youtube video of similar gx470 engine shows that the dealer is correct. I elected to skip the Cam seal replacement.