torque converter

[wriggs]

Hi all, I have been looking at a stag project which needs some bodywork which isnt a prob, but the guy says it needs a new torque converter.
Is this a major or minor job and what is involved?

[Staggard]

Hi yes fairly big, Gearbox out bell housing off starter out undo the coverter from the flex plate.I not sure if you can remove the bell housing with the engine in situe im'e sure one of the other lads can answer this. Good luck Graham

[Kevin Garrod]

Yes, gearbox can be removed with engine in.

[marshman]

Hi,
If its a BW35 then its a straight forward if long job. The gearbox is heavy so preferrably you need two people un less you have access to a ramp and a transmission jack. The basic sequence is as follows:

0. Disconnect battery.
1. Remove rad (to allow engine to tip down at the back - if you don't then the fan hits it.
2. remove starter - pig of a job to get to the top bolt!
3. undo top bolts around bell housing
4. Undo bolts holding the converter to the flex plate - you access these through the starter hole - stops and stress on the flexplate when you remove the gear box
5. Remove exhaust - mid and front sections.
6. Remove propshaft
7. disconnect gear selector, wiring to inhibitor/rev light switch & speedo cable
8. drain fluid from gear box
9. remove breather and dipstick tube.
10. remove "anti submarine" bars/stays
11. support gear box with jack or transmission jack
12. remove rest of bolts around bell housing bottom
13. remove rear crossmember (four bolts to car body) leave attached to gearbox.
14. Lower rear of gearbox enough to allow access to remaining bell housing bolts - use really long extension on socket and access from rear of gearbox.
15. Lower gearbox further and slide out - be carful not to tip forwards after removal as torque converter could slide out.

Be prepared for some more fluid to come from the converter when you slide it out.

Its worth replacing the front and rear oil seals whilst the box is out of the car.

Refitting is the reverse of taking it out.

Roger

[Mike J]

Does the converter share the oil with the gear box. Does it have a filter. Mine is clunking between gears so hoping it just needs a top up. Mike

[marshman]

Mike,

Firstly, yes the converter and gearbox use the same oil.

What gearbox is it? Is it a BW35? If so when you top it up make sure you use the correct ATF. You need Comma AQF or equivalent. The Comma one seems to be the most commonly available. The ATF must be suitable for "older BW gearboxes". It MUST NOT BE a DEXRON type. The reason is DEXRON contains friction modifiers and the brake bands in the BW box are not designed for it.

Symptoms of low ATF level are usually "slipping" especially when going round left hand bends. Harsh changes can be caused by a multitude of things, but I don't think low fluid is one of them.

Roger

[Mike J]

Spot on Roger. It's a BW35 with Comma AQF. Are there adjustments that can be made or it a question of getting a new converter. Mike

[marshman]

Spot on Roger. It's a BW35 with Comma AQF. Are there adjustments that can be made or it a question of getting a new converter. Mike

Sorry Mike but I'm not an expert on the internal workings of auto boxes. Its worth checking that the fluid level is correct. Also probably worth checking the kickdown cable adjustment and that it is changing gear at the correct speed.

Is it "clunking" on the up change or down change or both? Is this a new problem?

Roger

[richardthestag]

IIRC torque converters work just fine or they give up suddenly. there are a load of fins / vanes inside and when one breaks it generally trashes the whole unit causing chaos and loss of drive.

You would normally fit a cleaned (recon) TQ when you fit a new / recon gearbox. So I would imagine that if replacing the TQ you would need to have the box cleaned out also.

Any idea why they think the TQ needs changing?

BTW harsh changes on a BW35 are often caused by a blocked breather. it runs from the top of the tailshaft along the transmission tunnel and up and around the back of the brake servo. people clamp them to give a more sporting gearchange aparently.

Mine was clamped tight when I first got it. unclamped it and the gearchange became silky smooth but had a tendancy to leak atf up the dipstick tube when left alone for a day or so.