Manta Workshop Manuals
by Preston C.
(Reprint from April 1995 OMC Blitz)
When I was asked to write an article critiquing workshop manuals for the Manta, I really had to stop and think about what things I would like to see covered that were not. I must admit that for me this was not an easy task, as I have found the Manta to be such an easy car to work on I've hardly ever found an instance where the manual didn't cover what I was doing. Now, I must qualify what I just said by adding there are many things I have not done that are covered in the various manuals, so some Manta drivers are better qualified to cite deficiencies in the manuals. I can say, however, that I have done much more than the average Opel owner. The following are what I would say are some of the most common workshop manuals which cover the Opel Manta.
The manual is probably the most common one out there. It, like many, is out of print but there are still many copies around. It is a very basic manual covering enough points for the average car maintainer and then some. It's main problem is that it covers all Opel models sold in the US throughout that period and thus it cannot cover each model in depth. Very often it will state the ordered procedure or removal/installation of a part, yet won't tell you the tricks for taking it out (i.e.: many parts require special tools, or specific manuevers to get them dismantled, and the book simply says "remove this; installation is reverse of removal"). One of its biggest letdowns is that even though it has in its title "1975," it offers little information about 1975-specific items (i.e. fuel injection). When I had a 1975 Manta, the Chilton's was almost useless for working on the fuel injection. This manual is good to have for the basics, but for the hard-core mechanic or 1975 owners, I would simply recommend getting getting other manuals,
This used to be more common, but I don't see them around too much anymore. This is very similar to the Chilton's. About the only more interesting thing in it is the appendix where it goes very briefly into performance parts (i.e. dual Webers). Again, it only describes these modifications briefly and doesn't go into depth about setting them up.
This is probably the best non-dealer service manual out there. The authors claim it's based on an actual tear-down of an actual car. Thusly, it contains some tricks for the backyard mechanic. It doesn't cover 1975 Mantas so don't expect anything on fuel injection. In all honesty, the Haynes covers most all mechanical projects I have done on any non-'75 Manta. It's drawbacks are in the body section. It doesn't cover window mechanisms well enough and there are many things that still say "remove this" that require unmentioned tricks for removal.
Opel Factory Service Manuals 1971-1974 (and the 1975 "Supplement")
By far these are the best resources you can have for working on your Manta. These go more in depth than most people will ever need. There are parts that aren't mentioned though; for instance the glove box light. If you do your own work on a 1975 fuel injected Manta the 1975 "Supplement" is a must. As far as I know the 1972-1973 manuals include other models like the GT; the 1974 is more exclusively Manta (and the Ascona and Wagon which are mechanically very close). (Note: The 1975 manual is a thin supplement which covers only the parts changes for that year, such as fuel injection. If you need comprehensive information for a 1975 Manta, Ascona, or Wagon, you will also need a general manual like the 1974).
Unfortunately with all these manuals, they are getting increasingly hard to find. When you do find them they tend to be a bit pricey. If you do a lot of hard-core work yourself the factory service manuals are worth getting even at a high price. If you do minor work you'll get away with using the Haynes, and to a lesser extent the Chilton's. Again, for working on a Manta these manuals I think cover the topics sufficiently. Mantas are just very easy to work on. One thing that would be handy is if they would tell you what size bolts, wrenches, and sockets to use, but that of course would have made editing them prohibitively expensive. I would suggest that if there's a procedure you do often, write it down on a sheet of paper the size of tools you used so the next time the job will go much faster. And if you do write it down, send a copy into the Blitz so perhaps at some point we can put together a list of common jobs and the exact sizes of the tools you'll need. I know there are certain jobs I've done enough times that I always remember what size tools to use, but you can't do that for everything. I find that a lot of time does get wasted fumbling around with different size sockets, trying to find the exact one to do the job.