Strange overdrive behaviour

[Niha]

Hi All,

 

Yesterday I went to see a 1975 Dolomite 1850HL

The car looks sound with just one rust spot located where the front lower valance attaches to the left wing. The price was quite high but compared to lower priced cars, this one seems one of the better cars.

My greatest point of concern is that the synchro on second gear is weak and a, to me, strange behaviour of the overdrive.

At first sight it works as one would expect, but after a few km with overdrive engaged, it reluctantly disengages. After seconds to perhaps 10 or 20 seconds it finally releases.

The owner says that up to now no one found a solution.

Is there anyone who experienced this problem and found the reason? Perhaps it is easy to cure, but in the meantime one of the reasons to be reluctant to buy the car.

 

Any advice is welcome!

Nicolas

[Steve P]

I had a similar problem on my Herald with overdrive,it was the solenoid not disengaging properly,it cost about £170 for a new one fitted by Mike Papworth.

 

He said they can be repaired but the success rate is only 50% so i fitted a new one.

Could also be low oil level or crud in the filters.

Steve

[Pete Lewis]

if this is a dolly it could have a J type  sol on passenger side

 

the solenoid plunger gets goo'd up ,, easy to unscew and strip the innaeds from the solenoid and clean and makes amazing difference

the O rings inside the main body are accessed by removing a small 10mm circlip and give it tap on the bench to shoot the offending out of its tube.

 

 

D Type  sol on drivers side 

 

more fiddly needs the solenoid to be free and not rusting inside the lever on the side has a hole to align the adjustable stroke

there is a small hole in the spool valve on the top this may get clogged, 

 

 

but common to all is low gearbox oil level and shorting worn wires up the inside of the gear leaver, coupled with inhibitor switch going green inside or not set correctly 

 

all simple enough  DIY.   give a sunny morning and a good cuppa  

 

filters do get  up goo'd up  and need a clean from time to time 

 

there little to go wrong with the actual mechanics of  either of the units 

 

Pete

[daverclasper]

Hi

 

I had problems with a J type when first bought car.

 

It would not engage. not disengage and even engage when not switched on. (never use reverse if o/d is engaged as likely to trash o/d apparently)

 

Dave Twigger from overdrive spares was very helpfull with advice and sells o rings, circlips etc at a very good price.

 

I changed o rings in pressure relief valve (bit fiddely and had to make a very simple tool) and cleaned small canister filter. These are both located behind plugs, behind the screen filter in the sump and need a special tool to unscrew them, though I unscrewed them with hammer and punch.

 

Also cleaned and new o rings in the solenoid.

 

Been fine for 3 years now.

 

Dave

[thescrapman]

All Dolomites will be J-type, and as you are looking at an HL, it will be attached to a single rail box.

 

If the car is in excellent condition, that is worth far more in lack of grief than even fitting a rebuilt Overdrive will cost.

 

Negotiate a little bit off the price.

 

Cheers

 

Colin

[daverclasper]

forgot to add

 

Buckeye Triumph do a very good article on smaller jobs and rebuilding J Type on the tinternet.

 

Dave