I have just had the rear diff rebuilt and also changed the tranny fluid with new OEM MTF, but seems on cold days when the car has been sitting, its really hard sometimes to get the gear into reverse... any clues as to where I should investigate this problem?

 

The shifter lube TSB was intended to help with reverse gear selection, it's an easy DIY, and does improve shifter operation.

 

I always put it in 4th first then go to reverse on a cold morning, makes getting in much smoother/easier.

 

With pulling out the shifter and reapplying the urea grease? I did that probably a year ago and really filled it in with the grease. I also just did a full diff rebuild so thats also ruled out.

 

You never heard of the first then reverse rule???? Or is that just me because I came from driving a 1990 civic and had to do that every time

 

^ thats what I do on cold mornings. I've regreased mine twice and it still does it sometimes.

 

Yep, put it in a forward gear first and reverse should go in without much trouble. Let the gear out and bump the car forward a tad first if you have to.

 

doing a double clutch can help too along with the first gear selection, take it out of first into neutral, release the clutch, then engage the clutch again and proceed to reverse. It takes a bit more time and effort but it can help in some situations.

 

Check the clutch fluid level. I had difficulty getting the car into every gear and this was my issue. Topped off the reservoir and it was like night and day! This is probably the easiest check out of the suggestions given so far. Good luck!

 

check the clearance on the clutch rod too, it can help if the clearance is too big, it's not related to cold weather or temp changes but one more thing to help with overall smooth gear changes.