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OD engages slow

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duckspuddle

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My A type overdrive usually engages almost immediately, somethimes with enough of a jerk that I feather the clutch a little just to smooth it out. Just this week, it has begun to take about 2 seconds to engage, and the shift is very smooth. Nothing else has changed, and the gear box is full. The disengagement is immediate. Any ideas?
 
Check all of your electrical connections. I had the same problem that turned out to be a broken connector.
 
You may want to pull the drain plug on the unit and check to see how much metal has accumulated in it. I always feel like the ancient mariner cornering the wedding guest when recommending that folks use their clutch when engaging overdrive. You really can avoid a lot of unnecessary wear and tear on the brake ring, sliding member lining and annulus assemblies. A clutch driven plate is a heck of lot cheaper (and easier) to replace than any of those others. Every time you drain the oil and find those shavings in the bottom of the oil plug, they're all from those pieces. If you can get in the habit of using the clutch every time you'll see the amount of that detritus greatly diminish. But check it and let us know.

Tom Lains
TS8651 & 58107
 
In 48 years, I have never once used my clutch when shifting into overdrive or out of overdrive. Do you really think that Ken Richardson who prepared the works rally and race TRs in their early days would have accepted to lose time in a race or in a rally corner at speed, if he had to tell his drivers to use the clutch to shift into or out of overdrive. Never!

Don Elliott, Original Owner, 1958 TR3A

https://www.triumphest2006.com/images/clubcars/30donelliott'str3.jpg
Photo taken at VTR 2001 with the Ken Richardson Trophy
 
I think TRTEL is looking after longevity at the expense of speed/power shifts where KR did not need his car to run but relative short periods of time and had a pocket book of unlimited funds.
 
I would consider Don's 48 years to be more than "a relatively short period". The factory never recommended using the clutch. I have gotten 50 years, no clutch, & OD still in good condition. The type A is considerably stronger than some of the other models & may have something to do with the results. I think it's all a matter of personal preference with no clear cut "best way". OTOH, if your transmission is on it's last legs, clutching "might" make it last a bit longer.
D
 
I appreciate the comments about clutch use with OD. Does anyone have any ideas about why my A type shifts much slower and smoother than it used to? It used to be a kick in the pants shift especially from 2nd or 3d direct into over drive, now it shifts more like a J type, slower and smoother. It still shifts every time without slipping, but I wonder if something is getting worn.
 
Dave, the short run comment was directed to competitive events; not the sum of the 48 years. Personally, I think years is less important than the sum total of power that was transmitted when the O/D clutch engages. Reduction of the stress when engagement occurs would produce a longer life; on the other hand, I've never done a controlled test. BTW, if you drive a Triumph an average of only 3k a year (for 50 years), you are past due for a new clutch /ubbthreads/images/graemlins/wink.gif
 
I can't say for sure why the sudden change to a smoother shift, but I can offer my experience/observation this summer with my TR4A that has an A type.

I installed the A type last year and it gave the hard shift right off the bat (much harder then the A type in my TR3A). I drove it like that for about 300 miles then I changed the oil in the tranny/OD (since I had repaired the tranny lay shaft and bearings and then added an O/D to it I thought there may still be some bits from the old destroyed bearings I may have missed). The oil came out a bit cloudy for my taste and I hope it is just left over stuff from before. Anyhow I then put in new oil (the racing stuff Don sugested) and now it shifs more like the TR3A (that is smoother then before). It is still fairly instant an not 2 seconds like you describe. One other thing though was that the oil leven in mine was a bit low when it shifted hard.
 
I don't know about the A's, but the J's have a filter. Ever clean or change it? Check out John Esposito's web site or even call him for an expert opinion. He is great to talk to and will offer advice when he has an answer, which is nearly all of the time.

He has pictures of a blocked filter on his site and it ain't pretty.

https://www.quantumechanics.com/
 
This may be just a dumb thought (and comment) but could this be just a matter of ambient temprature and viscosity of the trans oil? The cooler it is the thicker and stiffer all fluids get, therefor the change in shifting behavior.
I, along whith all Canucks /ubbthreads/images/graemlins/canpatriot.GIF, experience this phenom. every year. In extreme tempratures, I have driven automatics that will not shift due to cold or frozen trans fluid. (-36 below zero F. yes: /ubbthreads/images/graemlins/pukeface.gif )
 
I have an original Lacock manual, which I will examine tonight. I recall there was a specification regarding engagement time folowing energizing the operating solenoid. But, remember this can get complicated because there are many variables. Things that I would look at:
- voltage that is delivered at the solenoid
- free mechanical operation of the solenoid, is it free to move, clean, not gummed-up, etc.
- condition of hydraulic fluid (oil), the viscosity of which will change with temperature as previously stated.
- more advance test will require a high pressure hydraulic guage, 0 to 500psi, and do the test in the shopmanual. You may have a marginal pump.
Also, I would monitor this for a while and try to correlate with some of these variables and note if the condition is stable of is getting worse.

BUT, dont worry, these units are robust and serviceable and all major components are available.

Cheers,

Frank
 
When Bill Piggott was at Triumphest in California a number of years ago, the TR2 someone had lent him for the weekend, shifted slowly into overdrive (like 15 minutes). Bill reported that much later, the owner found the answer. When the owner had it apart earlier, he had put two "O-Rings" on the cross shaft at the solenoid end and when the cover plate was put on, it had over-compressed the seals and squeezed them on the shaft causing too much friction resulting in the slow shift.

Have you done something similar recently ?
 
Rereading my post I realize that I left out the main thought that I was intending to convey. That in case there was an impending failure in the system the impact may be lessened by using the clutch and may allow for the cone clutch to engage without further slippage. If in fact that was the problem. Everyone's correct on the usage, just hit the switch. I raced my older car in the early 70's and it had been a race car from about '59 on. Having crewed and worked in the garage on it and customer cars while in college, I became very familiar with the internals. While the units are virtually bulletproof under normal use, racing will bring out the gremlins, which can lead to some truly catastophic failures if not attended to. I just didn't want to see him ruin a basically sound unit.
Tom Lains
TS8651 & 58107
PS. Most of the springs in the racecar OD are from a Healey unit for more pressure.
 
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