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Adrio
06-22-2005, 06:55 PM
The tranny on my TR3 pops out of second gear when I let up on the throttle at high RPM. Or put an other way if I am using the engine to brake it pops out of second. All other tranny functions are fine.

Any idea what is causing this?

aeronca65t
06-22-2005, 07:14 PM
Generally, this means a bad synchronizer. The trans would need to be removed and fully disassembled to repair this problem. Meanwhile, if you intend to drive it as-is, I'd change the trans oil on a regular basis to get any metal pieces out.
In some cases it can be a bent shift fork, but this means taking it all apart too.

AltaKnight
06-22-2005, 08:00 PM
What kind of transmission oil are you using?
It's been noted that synthetic oils will cause this to happen.
There's another thread running around about transmission oils, maybe check that out.

sammyb
06-22-2005, 08:47 PM
I have the same problem and it is not a bad synchro...synchro would normally cause popping out under acceleration.

What it is (and I have inspected it after a Triumph tranny expert pointed out the flaw) is the brass bushing sleeve around 2nd gear (part 25 on the diagram at https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29132 .) When that part wears, the whole sh'bang can move on the shaft and under engine braking, the gear and bushing slide forward and away it pops. If you remove the top of your tranny you can slide it back and forth with your finger if it's worn. (Which mine is!)

ron wilson
06-22-2005, 10:27 PM
Have a 59 TR3 A and when car is first started (first 20seconds or so) there is a rattle in the engine (also seems like the oil pressure does not register emmediatly and appears to register at the same time the rattle goes away. Has good oil pressure after that period (about 65)
and continues to be good the rest of the day. Never below about 40.

TRTEL
06-22-2005, 11:41 PM
Sammyb has it likley diagnosed. The common problem with them on high mileage boxes is that the thrust washer flange breaks away from the bushing portion (they are nicknamed 'tophat bushings'). Triumph engineers in their infinite wisdom place an oil groove all the way down to the mainshaft on the front side. Unfortunately this leaves about 3mm of brass(bronze) over a half inch distance. Guess where they always start to crack. So if you're putting it under a lot of load all the time (autocrossing perhaps) it's gonna go. Eventually if the two pieces start leaving chunks it may effect getting into gear. Or it could just be a really worn out gear.

Geo Hahn
06-23-2005, 12:05 AM
Off hand I can't think of a way to directly connect a rattle with an oil pressure problem. Put the bonnet up and see if you can pinpoint the rattle location... I always get my wife to help with this telling her to point where she thinks the noise is coming from -- she is better at that than I am.

BTW - if the rattle doesn't occur when the bonnet is up then it is probably the fitting where the hood prop connects to the front of the bonnet. They can get so loose that they start to bang around if the engine is idling roughly at start-up.

Dave Russell
06-23-2005, 01:04 AM
[ QUOTE ]
Have a 59 TR3 A and when car is first started (first 20seconds or so) there is a rattle in the engine (also seems like the oil pressure does not register immediatly and appears to register at the same time the rattle goes away. Has good oil pressure after that period (about 65)
and continues to be good the rest of the day. Never below about 40.

[/ QUOTE ]
Hi Ron,
I don't want to alarm you but I have known engines to make a light rod bearing rattle under no load, if the oil pressure is missing after start up. 20 seconds is a very long time to build oil pressure. It would appear that the oil system, maybe the filter, is draining back during shutoff. Many oil filters, or their connections, have an anti drain back valve to prevent this situation. I don't know your exact setup, but I would try to correct the situation. "Dry starts" can definitely shorten an engines life.

Large piston skirt clearances can also make a cold start rattle but it takes longer than 20 seconds to quiet & isn't related to oil pressure.
D

ron wilson
06-24-2005, 10:56 PM
Thanks for the suggestion geo but I lifted the hood up and held on to the prop and had the Mrs start the engine and it is hard to tell because my exhaust is so lowd but do think that is the problem. I'm not lucky enough for something simple.

ron wilson
06-24-2005, 11:02 PM
Thaks Dave for the suggestion. I have a fram filter #PH 2870 A which was on the car when I bot it 2 years ago. I cannot tell you if the rattle started some time after I bot the car or if it was doing it at time of purchase (it was warm then)
In my tinkering I also noticed if I pull the coil wire so the engine will turn over but not start that I can crank it for some time and not get any oil pressure. After it warms up I get pleanty of pressure at startup.
Any suggestions as to where I can get a filter with the anti drain feature??

Also this post is not in the correct place (mistakenly got it in the middle of the question re the fellas 2nd gear problem. So if the post shows up in the proper place it is not that I am ignoring you just trying to get it right.
Thanks Ron

ron wilson
06-24-2005, 11:16 PM
Do not know if this has anything t do with your problem but when I purchased my TR3 a couple of years ago it was popping out of 3rd gear on decelaration and I had the transmission overdrive and clutch all rebuilt (they replaced all of the items that have been mentioned so far) It still popped out of 3rd. And it appears the problem was a part called a Detent ball and spring that could be replaced by merely taking the top off of the transmission. This is all I know about it being a neophyte when it comes to transmissions (obviously) but at least all else is new.
Do not know if this has anything to do with 2nd gear but am certain someone on the forum can tell us.

Adrio
06-25-2005, 12:31 AM
[ QUOTE ]
It still popped out of 3rd. And it appears the problem was a part called a Detent ball and spring that could be replaced by merely taking the top off of the transmission.


[/ QUOTE ]

Thanks for the tip. It would be nice if that is all it was. I have a spare tranny but I would not want to swap it just for a simple thing like that.

Dave Russell
06-25-2005, 04:45 AM
[ QUOTE ]
I have a fram filter #PH 2870 A which was on the car when I bought it 2 years ago.
In my tinkering I also noticed if I pull the coil wire so the engine will turn over but not start that I can crank it for some time and not get any oil pressure. After it warms up I get plenty of pressure at startup.
Any suggestions as to where I can get a filter with the anti drain feature??

Also this post is not in the correct place (mistakenly got it in the middle of the question re the fellas 2nd gear problem. So if the post shows up in the proper place it is not that I am ignoring you just trying to get it right.
Thanks Ron

[/ QUOTE ]
Hi Ron,
Yeah, I know it's in the wrong place but I don't know how to move it. My apology to folks for getting in the middle of their topic. I'll keep it short.
Fram filters are not noted for being very high quality. I'm not surprised if the anti drain back valve is not working. also, two years is a long time to run on any filter. If you are sure that the present filter is the correct one for your application, I would suggest finding & substituting a K&N HP2005 filter & trying it. Pretty sure it will cure your problem.
D