# Knocking from Trans



## saudade (Apr 10, 2010)

1986.5 D21, Z24i, 2wd, manual, 220K. Son came home saying there was a knocking sound coming from the engine. Took it for a drive and it's not the engine. No odd sounds coming when the clutch is depressed. However, in neutral I can hear a faint knock. Hard to hear when you rev the engine. When in gear, no problem hearing it. It changes with speed as long as there's a load on it. Back off the gas or press the clutch and it almost vanishes. It's loudest in 3rd gear. It shifts normally and he says he didn't have any trouble shifting.

Crawled underneath to have a look and discovered the carrier bearing was toast. I mean like Texas toast. Had at least 3/4" lateral play with the boots almost completely gone. So had to pause and fix it since I can't leave my truck on jacks for too long.

Sadly, but not unexpectedly, the problem persists. Laying underneath, you can hear the knock better. Still slight in neutral, hard to tell if it's rpm dependent, goes away when you depress the clutch. I put my hand on the trans and can feel the beat.

So I'm thinking, it's not the clutch/throw out bearing since it's waaayyy worse in 3rd gear. Not the output shaft since it does it when not moving. Input shaft? Bearing or 3rd gear?

Gonna drain the oil and look for metal. Honestly, it probably doesn't matter. Looks like the old girl is heading to the great scrap heap in the sky.

We are the original owners so this is a sad day. :crying:


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## jp2code (Jun 2, 2011)

It sounds like a tooth broke on one of the transmission gears.

Replacement transmissions are not too expensive if you can find one in the local yard.

Or, if you are not interested in trying to fix it, there are many people who like these trucks. You could post it on your local Craigslist with a lot of pics and description of the transmission problems.

You should be able to get more than scrap prices.


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## smj999smj (Jan 1, 2006)

I would look for a used trans. Try Car-part.com or have your local salvage yard locate one. These trucks still get pretty good prices if you do decide to sell it, especially if the body and frame are rust free and in good shape.


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## saudade (Apr 10, 2010)

Here's an update. I called around for a rebuilt trans. Would cost locally about $1000 just for the trans. Take it to shop and have them rebuild it and replace the clutch is closer to $1800. Junker trans would be more like $250 but no guarantee and I'd still have to replace the clutch. Sadly, it's outahere... Been in the family since new (1987). It's time to move on.


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## jp2code (Jun 2, 2011)

If it's been in the family since new, only you know if the vehicle is worth spending some money on.

You certainly are not going to get a new vehicle for that price. In my personal experience, the last 3 used vehicles I bought quickly cost me double their buying price.

Food for thought. $1800 on a good rebuild, and you should be able to get another 100K miles easy. As long as you are maintaining the engine with oil changes and such, the Z24i often lasts to 400K miles before needing attention.


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## saudade (Apr 10, 2010)

Yeah, I hear ya. There are just other issues, like warm AC, broken off trim parts, rip bench seat cover, some body damage and such that would require a pretty big investment to make it reliable once again. And it would still be a 30+ year standard cab, short wheelbase, old truck.

My son would now rather have a sedan of some kind with a backseat and trunk.

Here are some of the things I fixed over the years (well, since becoming a subscriber here).

Bad ECU Connection
http://www.nissanforums.com/hb-truck/249810-intermittent-poor-running-fixed.html

Head Gasket
http://www.nissanforums.com/hb-truck/179065-lives-again.html

Bad Harness Splice
http://www.nissanforums.com/hb-truck/160226-86-5-z24i-engine-cutout-solved.html

Stolen
http://www.nissanforums.com/hb-truck/172221-its-gone.html

Water Pump
http://www.nissanforums.com/hb-truck/169115-waterpump-sunday-morning.html

Water Leak
http://www.nissanforums.com/hb-truck/161461-86-5-d21-heater-box-drain.html


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## saudade (Apr 10, 2010)

serica said:


> good idea. my nissan car always have problem at front lights


Ah, nothing like a side of spam to go with your lights.


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## jp2code (Jun 2, 2011)

serica said:


> good idea. my nissan car always have problem at front lights





saudade said:


> Ah, nothing like a side of spam to go with your lights.


Yeah, I reported it yesterday, but so far no Admin has come forward to take action.

Meanwhile, do not follow the link in his title. It's a virus.


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## saudade (Apr 10, 2010)

Well. This story has finally come to an end. Donated to help disabled veterans.


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