Gear change crunch

[mitchelltjohn]

changing from 4th to 3rd I get a little crunch in my 5-speed gearbox. When I ease gearstick back and try again it slips into 3rd ok. Bit of a pain as makes for slow down changes. Doesn't happen when changing up from 2nd to 3rd. All other changes ok also.

Also I need to fully depress cluthch pedal to floor to maek any changes - hopefully not sign of clutch wear, though there's absolutely no sign of slippage.

Any helpful hints or ideas appreatied...

John

1979 FHC pageant blue
1981 DHC triton green

[Beans]

Could be clutch wear, perished clutch hose, air in the hydraulic system, leaking clutch cylinders or knackered bearing(s) from the 'box's input shaft ...

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[FI Spyder]

Difficulty shifting into second (especially when cold) is a sign of incorrect trans oil. But shifting into third (besides things mentioned by Beans) could be worn synchros. If it is you should be able to shift from 4th into 3rd by double clutching with no difficulty (if done properly). Can you double clutch down into 3rd?



- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

[searider]

That's interesting as I have just bought a 7, with 2nd hard to get into. What is he correct oil? I have been told variously EP80, 75W/80 synthetic, or even ATF.

Thanks

[Hasbeen]

Yep John, believe Beans & bleed the system to help full disengagement of the clutch, then learn to drive around that worn 3rd gear synchro, by double clutching as Spyder suggests, or by matching the revs, with a little blip of throttle when going back a gear, as I do.

I have never owned a 7 that did not have at least one tired synchro Second gear on my first, 4Th on my second, & 5Th on my third. Learning to drive properly again, after years of sloppy synchro dependant driving has returned the joy of motoring to my driving.

My current 7 has slow synchro on one gear, but for the life of me, I can't remember which. Driving properly has meant it is so long since I had one of those crunches, I have totally forgotten which gear it is.

There is another unpleasant possibility. The clutch fork on these wears, or deforms at the pivot point. As this happens clutch actuation becomes progressively worse, until it fails completely. This is a gearbox out repair. Lots of labour, but not too much expense in parts fortunately.

Hasbeen

[mitchelltjohn]

I went out last night to try double de-clutching / rev matching, and each time I was able to change cleanly between 4th and 3rd.

I can try bleeding the clutch fluid to see if that makes any diffence.

I have a spare new clutch fork but, but having changed clutch in my other TR7 a few montsh ago takign the geaxbox out is not something I want to do without being sure it will fix the problem.

If there is a sychro probelm on 3rd gear, what does that mean in terms of fixing/repair in the geaxbox?

John

1979 FHC pageant blue
1981 DHC triton green

[Hasbeen]

John I've been driving my current 7, with a very tired synchro on one gear for 10 years & 60,000Km. If something actually breaks, or the clutch dies, & thus the box has to come out, I will probably overhaul the box. Otherwise I will continue to drive it as it is.

I raced F1, & F2 Brabhams & Lotus back in my younger days. These had the Hewland trans axle, which were dog engagement boxes, which can not have synchro fitted. A box with a synchro that is a bit dodgy is therefor has no worry for me.

With a bit more practice it should be no worry to you.

Hasbeen

[mitchelltjohn]

hasbeen/others, thanks for the helpful replies...its appreaciated.
John

1979 FHC pageant blue
1981 DHC triton green

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by searider</i>

That's interesting as I have just bought a 7, with 2nd hard to get into. What is he correct oil? I have been told variously EP80, 75W/80 synthetic, or even ATF.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Much discussed, do a search to get pictures etc. The short answer is Pennzoil Synchromesh (not the synthetic version). There is a GM equivalent that a search will show up but I suspect it will be more pricey compared to Pennzoil that should be readily available at your local auto parts store.



- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by searider</i>

... with 2nd hard to get into ... <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
That's pretty normal on the LT77 'box when cold.
With proper oil (use the search function) this shouldn't be an issue
when the 'box & oil are on normal working temperature.

Forcing gear changes into 2nd gear results in this kind of damage ...



<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>